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What's wrong with my boiler?

(35 Posts)
Worried345 Wed 20-Feb-13 13:55:18

Gas central heating Potterton Nettaheat boiler began to flare in fits and starts rather than stay on this morning. It's now finally died.

Got someone coming out tomorrow to have a look but in the meantime, can anyone knowledgeable suggest what it might be? Will it be days/weeks before we have heating and hot water again?

I'm trying to recover from pneumonia and flu - after over 2 weeks being ill - and am still feeling very unwell - so am panicking a bit about the ice cold house - particularly for the nights - and also for the sake of the DCs.

PigletJohn Wed 20-Feb-13 15:19:54

The Netaheat was an advanced boiler in its day, but is now rather old. I've had one, and also the Profile which replaced it. Heating engineers love them.

If you can get the parts to keep it going, it is reliable.

However its efficency will be far below modern boilers; I haven't looked it up but depending on model will be in the region of 60% - 65%

A modern boiler can be 90% efficient or more so likely to knock a third off your gas bill. However it will take years before this covers the cost of a new boiler, so don't be too hasty.

I imagine you have a hot water cylinder with an immersion heater, and the cold winter is drawing to an end, so don't be pressured intoi a quick decision. You will find special offers and price reductions building up as winter recedes, and the best people will be getting less busiy.

You can get a good modern condensing Conventional or System Boiler, with stainless steel internals that will not corrode, that will swap in as a replacement and can be quite small. Don't get talked into a combi unless you have a small home with only one bathroom. Personally I would avoid any boiler with an Aluminium heat exchanger, but they can be bit cheaper.

Worried345 Wed 20-Feb-13 17:51:05

Thanks for the advice, PigletJohn. You know when you said, "I imagine you have a hot water cylinder with an immersion heater, and the cold winter is drawing to an end, so don't be pressured intoi a quick decision", was that implying that there might be some way of us still getting hot water even if we can't get CH?

I'm clutching at straws here but obviously the main thing we need is hot water rather than heating as we can put on coats. The urgent need is for the hot water and so I'm dreading the service guy saying that it'll be weeks before they can get parts or even fit a new boiler.

However, when the boiler died this morning, I assumed that the hot water was off too now? So I've turned off the system. Are the two things connected - ie if the boiler isn't flaring into flame, then presumably the hot water is also off too?

Sorry I'm so ignorant. By the way, how much - v v roughly - might a whole new boiler cost these days?

PigletJohn Wed 20-Feb-13 18:08:26

If you have got a hot water cylinder, which I expect you have, with a Netaheat, in an airing cupboard, then it has probably got an electric immersion heater. What colour is the cylinder?

You will see a round plastic cap, probably off-centre of the top of the cylinder, with a white flex coming out of it and going into a switch on the wall. This will heat your HW when the boiler is out of action.

If you have never used it it, it might or might not be in working order, but a plumber can easily fit a new one.

A boiler change will cost £1 to £3 thousand. Ask local friends and neighbours for their recommendations of a good local installer. When you call, always start by asking "do you repair boilers" because if not, he may not be very good.
He must of course be Gas-Safe registered (Corgi is replaced now)

Worried345 Wed 20-Feb-13 18:59:17

Thanks. Our old hot water cylinder had the flex connected to the switch on the wall in the airing cupboard but this has been disconnected and the wire left dangling and cut through.

The new cylinder seems to be greenish in colour (looks like integral insulation). There's no white flex coming from the black plastic top which I can see on top of the cylinder.

However, there is a white flex coming from what looks like an orange pump-like thing which is attached to pipework near/coming from/ connected with the cylinder. This white flex comes out of a black plastic thing attached to the orange pump thing and leads down to a round black plastic enclosed thing on the floor. Would that be the connection however to the downstairs bolier rather than a separate electric immersion heater?

There's a tiny silver coiled wire coming from a valve thing on a copper pipe about halfway up the cylinder, that seems to be to do with the temperature gauge. This goes into some part of the cylinder that's covered in silver sticky tape with a red spot on it, which I presume indicates something important?

Is there anything, from what I've said, that might indicate how I can switch on the immersion heater or has this system been disconnected?

I'm hugely grateful for any further advice and obviously won't do anything that might put me or the family at all.

PigletJohn Wed 20-Feb-13 22:44:45

"Our old hot water cylinder had the flex connected to the switch on the wall in the airing cupboard but this has been disconnected and the wire left dangling and cut through. .... There's no white flex coming from the black plastic top which I can see on top of the cylinder. "


sounds like some idiot didn't bother connecting it.

It sounds like a new cylinder was fitted and, if there is a black plastic cap, it has got an immersion heater fitted but for some reason not connected.

With luck it will have been left just be for laziness and can easily be reconnected. However I'm not there so I can't see it. Any competent DIYer, plumber or electrician will be able to connect it, but a competent electrician will be able to test the circuit and if necessary repair it. There might possibly have been a fault which was the reason for not connecting it.

In your fusebox (consumer unit) there is likely to be a fuseholder or MCB labelled "immersion heater" and marked 15A or 16A. It might be blue. This will supply the immersion heater which should be on its own circuit. I hope it will be turned off or the fuse removed, since the flex in the airing cupboard has been cut and left and could otherwise be dangerous.

An electric immersion heater in a hot water cylinder is a very useful thing to have, as it gives you hot water when/if the boiler is out of action. This is a great advantage over a combi system which has no fallback.

It is very annoying that yours has been left unconnected.

A cylinder with green insulation might be about ten years old, which is fairly modern. New ones are blue. Older ones were yellow.

PigletJohn Wed 20-Feb-13 23:01:11

"tiny silver coiled wire coming from a valve thing on a copper pipe about halfway up the cylinder, that seems to be to do with the temperature gauge. "

this sounds like it might be a Drayton Tapstat, which used to be used on older gravity HW systems. It stops the water circulating to the cylinder once the cylinder is hot enough, to save energy and prevent the water overheating. The silver wire is actually very small bore pressure pipe, and must never be cut or sharply bent. A new one is over £100 but these days a different method would be used. Or it might be a Cylinder Thermostat, and the spring is like curtain-wire to strap it to the side of the cylinder.

"orange pump-like thing which is attached to pipework near/coming from/ connected with the cylinder."
This is probably a Grundfos pump, which circulates the hot water from the boiler around the radiators, subject to the room thermostat and the CH timer both calling for heat.

I don't believe any of these will be connected with your boiler fault.

If you have anyone in, who says he can repair the boiler, ask how much he would charge to fit a Sentinel or a Fernox System Filter (this will trap the sediment and sludge which your system is bound to suffer from, being so old. Don't accept a Magnaclean, they are very effective, but they have a bad reputation for developing leaks. This is not urgent, but will be worth doing, especially if it can be combined with other work to avoid an extra visit. I can tell you more about sludge and sediment later).

MumVsKids Wed 20-Feb-13 23:04:56

I've just bought a central heating complete package for £1128 inc vat. You can buy boilers from just over £400 inc vat.

Cheapest place (according to my plumber DH who is fitting our new heating system) is

Hope you get sorted soon.

MumVsKids Wed 20-Feb-13 23:10:43

We're just changing from a 10mm microbore system to standard 15mm. The sediment and sludge in our rads, along with an antiquated baxi Bermuda back boiler did not make for a very warm house.

Glad you've said about the magnaclean pigletjohn I was looking at getting one of those.

PigletJohn Wed 20-Feb-13 23:32:03

The Magnaclean was the first mass-market system filter, and really topped the market for a few years (I have an earlier, solid-brass Spirovent, but many plumbers had never seen one). It is made of plastic, with a screw-off plastic lid, and for several years was supplied with poor quality valves, which also leaked quite quickly.

I imagine Adey made a fortune selling a plastic tub and magnet for £100, but he must be kicking himself for the poor product quality which ruined his reputation. More than one large installer stopped using the Magnaclean due to the cost of warranty claims resulting from leaks. I put one on my old mum's boiler. It was fantastic at first. Then the cap leaked. Then the valves leaked. I don't want replacement parts or a guarantee, I want a well-made product.

PigletJohn Wed 20-Feb-13 23:33:50

"You can buy boilers from just over £400 inc vat"

And you can buy donkey burgers at 99p for 8.

I wouldn't.

Worried345 Thu 21-Feb-13 11:09:07

Thanks for all the input. I'm now waiting for the heating service guy to call - anytime till 3pm today - and desperately hoping he fix the boiler straightaway and also reconnect the immersion heater.

Only one day without hot water and everythins becomes SO much more difficult! Was up at 4.45am boiling kettles to heat bath water that we all used, one after another. Not had time to start handwashing dirty dishes that can't be put in dishwasher and the laundry is already mounting up. Sitting in 3 fleeces and a coats and scarf!

Hope we soon get hotwater at the very least!

GingerPCatt Thu 21-Feb-13 11:17:58

Worried, I'm no help with a boiler but is there a leisure centre or something similar nearby where you and the family could have a hot shower? When our boiler broke, I went swimming everyday just for the shower. Also get a little electric heater so at least you can be warm(ish) in one room. Hot water bottles/heating pads are great to warm up the bed. Do you have a friend or neighbor where you could wash up and do essential laundry?

Worried345 Thu 21-Feb-13 21:17:02

Thanks Ginger. We don't have time to go to a local leisure centre as I work daytimes and some evenings and weekends. No near neighbour or friend who can help either.

Bad news is that the boiler can't be fixed as it's too old for a necessary spare part. Cost over £100 just to find this out today. Getting someone back on Monday to see if they can reconnect immersion heater so we can get hot water. Hope this works - but it'll be yet more money and then....

Got to start getting estimates for a new boiler which I think is going to be a massive expense. The firm I'm currently using can't even do an estimate for about a month as their estimate guy is off sick. So I'll have to look elsewhere.

It could be months, from what they said, to actually get estimates, order boiler and arrange the time - with maybe at least a week off work for me - to get a new boiler put it! I absolutely can't take any more time off work either and don't have time to start calling round companies and arranging for people to come out and do estimates - but it'll have to be done.

Meanwhile, bought a couple of convector heaters so that we can at least warm up 2 rooms. It's already well below freezing tonight. Guess I'll be wearing my coat to bed! Still not recovered from pneumonia either. Why do these things happen at the worst possible time?

Regarding boilers, any recommendations as to what to go for?

PigletJohn Thu 21-Feb-13 22:47:51

I am guessing you just have one bathroom and no additional shower room? In which case a combi may do. But first, fill a bucket at the kitchen cold tap, time it, and calculate how many litres per minute it delivers (this is important for a combi). Also measure it at the garden tap if you have one, and report back.

If you can get the immersion heater fixed, and a few electric heaters (and preferably an electric blanket in the end-of winter reductions from Tesco or Aldi), the pressure will be off as soon as the weather improves, and you would find it difficult to get a new boiler fitted any sooner, so don't be rushed.

As expected, all the good heating people will be rushed off their feet at this time of year. Availability, and prices, will improve as soon as it gets warmer.

If by any chance you have to get a new immersion heater, ask for a dual-element Incalloy-sheathed one (they will know what this means) of the maximum length that will fit your cylinder (probablty about 30 inches) and for an Immersion Heater Timer to be fitted, with the clockwork wheel, not an electronic one.

Old plumbers are more skilled in removing old immersion heaters, which are often seized in place, without damaging the cylinder.

The two most popular good-quality mass-market brands of boiler are Worcester-Bosch and Vaillant. I have a Viessmann which IMO is a bit better and has a long guarantee, but they are less common, so be sure to have an Approved Installer as listed on their website. You can get a cheap boiler for about half the price, if you happen to want a cheap boiler.

You can get a combi or a regular (heat only) boiler, it will not make much difference to the cost of installation or running. For some reason, a lot of people think that if you get a new boiler, it has to be a combi. This is not true. As you have an old, open-vented system, it is pretty well essential that you have it powerflushed, and a system filter fitted, before the new boiler is connected to the dirty pipes. Always ask if this is included in any quotations you receive. If not it will cost £hundreds extra. You can get a boiler quote from BG, or any other supplier of Electricity or Gas. Generally speaking it will be more expensive than a local independent, but you can be 100% confident they will not go bust or run off with your money, and if you have a complaint they will (eventually) deal with it.

Combis are more complicated and go wrong more often than regular boilers.

As you have noticed, if you have a hot water cylinder with a working immersion heater, you can still have hot water even if the boiler is broken. This does not apply with combis. It is very upsetting that your immersion heater is not working, because it would have been a boon to you.

PigletJohn Thu 21-Feb-13 22:51:32

btw you mentioned laundry piling up.

Assuming you have a working washing machine, even it has Hot and Cold fill, it will work OK if the water is cold, it will just take a bit longer to heat it up. Dishwasher will work fine as it too heats cold water.

PigletJohn Thu 21-Feb-13 23:38:21

see also

MumVsKids Fri 22-Feb-13 00:44:44

We've just bought a 24kw Vaillant ecotech24 for £1128 inc vat, and that includes 7 rads, 7 trvs, 2 lock shields, inhibitor and fernox plus yards and rads of plastic 15mm pipe.
See previous link to

DH is gas safe and installing, along with decommissioning and removal of old system for grand total of £3650 for our landlord which includes everything.

PigletJohn Fri 22-Feb-13 12:52:40

(about immersion heaters, I just asked the makers, and they have stopped making the dual-element ones. Just get an Incalloy one as it will last longer than plain copper. The longer it is, the more hot water it will make as it will go nearer the bottom of the cylinder, which is important, if you want a bath. It will take quite some time, hence my suggestion of a timer so it can come on in advance of need. A well-insulated cylinder and pipes does not lose much heat.

Worried345 Sun 24-Feb-13 11:01:07

PigletJohn - you're extremely helpful! Thank you!

I've just timed the flow of water from the kitchen tap and the outside tap. The kitchen tap gives 1 litre per 2.5 seconds (not totally accurate as don't have large enough container really) and the outside tap was about 1 litre in 3 seconds.

What does that indicate please?

We have an upstairs bathroom and a downstairs shower room BTW and I was planning (before saga with boiler) to get a third shower room put in downstairs this year.

If you don't have a combi boiler, does that mean that all hot water is heated by an immersion heater only and if so, won't that take ages to heat up every day? However, I can see massive advantgaes to having 2 separate systems if a new boiler packed in again. It took 55 minutes to boil enough kettles for a lukewarm bath this morning - that I used last!

Distaster has struck with the washing machine. I put on a wash as it does indeed only have cold water feed. However, the water going in was slow and sporadic and then stopped and the on light flashed and the whole wash stopped. I started it all over again on a cold quick wash - again - it just stopped. Restarted on normal wash (it's all the white shirts and stuff for DCs school tomorrow!) and it did the same thing.

Will this be related to the lack of circulating hot water in the house? Could it be that the 1 hr of using water to boil kettles, drained part of the water system and there's nothing left for the washing machine?

I've tried just leaving it and seeing if it fills slowly and restarts but it doesn't seem to be doing this and I suspect that the machine itself has some mechanism that puts it off when the timing of water infill is 'wrong' or something?

Now I can't open the washing machine door and access the wet dirty laundry and DCs have no shirts for school. This isn't going v well today and the house is icy cold!

Any further advice is HUGELY appreciated!

PigletJohn Sun 24-Feb-13 13:09:21

1) Flow of water from kitchen tap sounds very good. I calculate you are getting about 24litres per minute, which is plenty. Have you got a fairly modern house with a blue or black plastic incoming water main up to your stopcock?

2) If you don't have a combi boiler, the usual setup is to have a well-insulated hot water cylinder connected to the boiler with well-insulated pipes. Most of the time the gas boiler will heat the water. Gas is much cheaper than electricity and modern condensing gas boilers are very efficient. A modern boiler can nominally heat a modern cylinder in 20 minutes (though in practice it is usually longer, especially in winter when the incoming water is very cold). When the boiler is out of action, there is usually an electric immersion heater in the cylinder, which will also heat it, though much more slowly as gas boilers are very powerful.

3) If the washing machine is not filling, it should not matter that you have a fault with your boiler. I think, unless it is a coincidence, that you might have turned off too many valves and the water is not getting through. When a boiler breaks down, unless it is leaking, you don't need to turn any of the plumbing off. The water will continue to flow, but it will be cold. You can switch off the boiler at its programmer or electrical switch if you want. If the washer has stopped mid-cycle, you can turn the knob to off, switch off or unplug it, after about a minute the door will unlock and you can take the stuff to the laundrette. But that might not be necessary. Are all the other hot and cold taps in the house running, WC cisterns filling, cold tank in the loft filling? The loft cold tank usually contains about enough water for one bath, so if you have drained it, and taps and pipes fed from the tank will now be empty.

I don't know how short money is, but you might like to get an electric oil-filled radiator from Tesco or somewhere, and see if their electric blankets have been reduced yet for the end-of-winter clearance. Oil filled radiators are safer than ordinary convectors as there is no red-hot element and they can't cause burns or fires.

PigletJohn Sun 24-Feb-13 13:22:11


as soon as the cold weather ends they will be half-price

Worried345 Sun 24-Feb-13 14:06:05

Many thanks again, PigletJohn. I wish I'd been taught all this kind of thing at school rather than stuff that I've never needed to know throughout the rest of my life!

No it's not a modern house: it's 1930s. I can't see anything blue or black plastic near what I think is the incoming water main/stopcock, although I'm not 100% sure that this is the stopcock/water main. There just seems to be a white painted pipe and an old fashioned copper/metal looking tap.

Still don't understand why the washing machine isn't working? As far as I know, the boiler man didn't turn off any valves at all when he was here and the taps and loos are all working, although the water pressure at the cold water tap to fill the bath seems to be less than usual. He just disconnected or put off the boiler itself.

I can't access the loft (no ladder) to look at the water tank and check if it's empty. Do they not just refill once water is used?

The washing machine definitely only has one cold water pipe coming down from ceiling to fill it. When I start any kind of cycle, some of the cycles do elicit a few gushes of water sporadically but then that stops and the start button flashes and nothing further happens.

Can't get out to look for a laundrettes without having to take the children, who will protest hugely. Not sure where there's a laundrette round here nor opening times. Will have to think what to do for the best.

I've got 3 electric conductor heaters purchased on Friday but that means only 3 rooms can be warmed and as soon as you put them off, the rooms cool down rapidly. Won't get time to get out to Tescos as I'm working all next week, including some evenings, except the window of time that the man comes to try to fix the immersion heater tomorrow - unless I can force the DCs to go there as well as a launderettes today.

Thanks for the links for heaters and electric blankets. Wearing so many clothes to sleep in that it's not really a problem. The main issue today is not having a working washing machine and the thought of having to get up tomorrow at 4.45am to heat enough water for our baths before school run and work!

PigletJohn Sun 24-Feb-13 14:25:02

count the number of flashes (e.g. flash, flash, flash, pause, flash, flash, flash, is three), and look in the washer instructions. Modern machines often self-diagnose and flash to indicate the problem. If you have lost the instructions you can download it from the manufacturer's website but you will need the model number.

Have you cleaned the machine filter recently to remove the socks, bra wires and loose change? Probably isn't that though.

It is such a coincidence that I would suspect the plumbing is not providing enough water. If you look under the sink you will probably see the plastic filling hose attaching to a service valve. If so, is it on the same pipe that feeds the sink tap? Does the sink tap flow OK? Are all the valves you can find open?

btw measure the water flow into a bucket or washing-up bowl to verify that it really is as high as 24 litres per minute - that is unusually high for an old house.

leeloo1 Sun 24-Feb-13 14:30:44

Disclaimer - I'm not at all an expert like PigletJohn, but...

We once had a problem with the heating not working. In the attic there's an open vent bit (ours looks a bit like an shorter version of an old round black bin - they're meant to have a lid, but ours doesn't) - above the open vent there's a ball float (like inside a loo). On ours somehow the float had got stuck up so new water wasn't getting into the system - when my dad we released it the heating magically worked again. It might be worth getting a ladder so you can explore?

There's no reason why your DW/WM have stopped working unless there's a problem with the amount of water being sent to them. Get someone to run a tap whilst you twiddle the old knob that you think is attached to the stopcock. Hopefully the water flow will improve and you'll have working appliances.

You have my complete sympathy with all the hassle - we had no boiler/kitchen/appliances for 4 weeks earlier in the year and it was a total nightmare! Luckily we got a new open-vent boiler at the end of it all, which is much better and more efficient than our 30yr old one was but I'm not sure it was worth all the heartache!

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