Boiler replacement options

[DIYamateur]

We live in an old Victorian semi-detached with a gravity fed heating and hot water system, with a cold water tank in the attic and a hot water tank in a cupboard in one of the (small) bedrooms. We have one bathroom but are planning to put in an addition toilet downstairs (and maybe a shower too).

The chap who does our boiler maintenance advised that our boiler is old, on its last legs and should be replaced soon. We could get a combi-boiler but he’s recommended a system boiler instead. We could put the boiler and cylinder in the attic and use the cupboard where the current hot water tank is for storage, which would be welcome. However the quote for all the work is quite high, close to £7k (I think the quote includes enlarging the loft hatch and putting in a new drop down door and ladder)! I’m now wondering if we can just replace the boiler (and hot water tank) and leave everything else as is. This would save on a lot of the labour costs.

The other option that it feels like we should consider is the heat pump that the government has been pushing. I think the house is reasonably well-insulated and we already have large radiators. With the government funding I think it could cost us less than the system boiler.

Any thoughts?

@Pigletjohn it would be great to hear what you think in particular!

"I’m now wondering if we can just replace the boiler (and hot water tank) and leave everything else as is. This would save on a lot of the labour costs."

Yes you can. It's a cylinder not a tank. You might benefit from replacing some of the old pipework.

If you have sufficient water flow into your house for a combi you could have an unvented cylinder, which is better. But as you have a Victorian house, you would probably need to replace the incoming water pipe with 25mm or 32mm plastic. Most likely it is half inch lead which is not big enough and might be leaking by now. Perhaps it has already been replaced. If you have lead pipes, ask your water co to test your drinking water for lead content. This must be done before you start work. Do it now.

Don't go near a heat pump unless you're going to massively insulate your home and upgrade the size of your radiatiors. Heat pumps will cost you more than double a regular boiler and they only produce an ambient temperature. They're ok if you can suppliment with a log burner. I know of people removing heat pumps and going back to regular boilers or oil.

I would get a salesperson from British Gas in. They are much more comprehensive in their quotes and will go through all the options with you. Then if you choose to risk it with an independent, you can use that information to inform the independent what you want doing.

Also, I would wait until at least April/May because the winter work for the heating engineers will be decreasing then, and you have more chance of getting someone to quote a decent price from an independent.

Finally, as per the poster above, I would not go with a heat pump. Too risky in an old build.

Crikey I wouldn't get British Gas in! They're notorious for trying to sell you stuff you don't need!

We replaced our boiler with a like for like one a year ago. We also kept our feeder tanks and a hot water cylinder and are happy with that.

We went with British gas after getting several quotes as they gave a few discounts and a discount off our existing boiler cover which made it no more expensive than the other quotes we got.

Also got 2 years interest free credit.

Thanks, this is all really helpful!

According to DH there is a reason why we apparently can’t just replace our boiler with a newer model, something to do with venting and the current set up no longer being allowed. I’m trying to get more info from the boiler guy and see if we can just update what we’ve got.

@PigletJohn in kind of shocked that there could be lead leaking into our water and the onus is on us to get it checked! Clearly I put far too much trust in the state. I don’t know if we have lead pipes but I’ll try to get the check done irrespective. Hopefully the water company will have a record.

It sounds like it’s worth having British Gas quote if only to understand our options better.

Well of the two independents I got in one wanted to drain the condensate into the soakaway, which is not awful but not great either.

The other told me my gas feed pipe was too small and wanted to upgrade it for an extra 2K.

BG however specced correctly, and even went for a lower power boiler than I eventually went for.

They also did all the proper regulatory stuff, which I have had issues with from independents in the past.

Wow, totally the opposite experience with BG - hard sell to buy stuff there and then, dubious discounts that made a boiler vaguely the same price as an independent, wanted us to sign up for the boiler care monthly subscription which then kept increasing in price and needed loads of chasing to get them to do an annual service even though it was included.

At our old house several local independents seemed to be ex-BG workers who'd left in disgust!

www.mumsnet.com/talk/property/4735316-boiler-question-mid-terraced-house

This thread may be the same issue.

As well as BG you can try BOXT. Generally they are much better on regulations and doing things properly without shortcuts than the independents. But are more expensive (sometimes substantially so).

Not sure I have ever met anyone who has worked for a big company who then leaves them give glowing reports. After all, if they were so great, they would not have left them in the first place.

I've been very impressed with all the BG engineers (about 4 different ones) I have met.

I've never had the hard sell from them, but I don't normally get a hard sell from anyone, including the most keen double glazing salespeople. I think it's the fact I sound like I know what I am talking about (I put a couple of days or so into researching boilers before I made my choice) and have a couple of high end scientific/engineering degrees so they know trying to mess me around on tech specs is pretty pointless.

I think you can get good independents (I have one guy in to do some plumbing occassionally). It's just that they can be very variable in quality and by the time you realise they are crap they might have cost you a lot of money. Generally in life you do get what you pay for IME. If someone is a lot cheaper, they are shortcutting something somewhere along the line.

Thanks, I’ll go through the thread but on an initial look many of the issues relate to it being a terraced property whereas ours is semi-detached. We have an alleyway separating us from our neighbours and it is on that side of the house that the boiler is currently located, in a chimney breast

If you only have one bathroom then get a combi.
No faffing around with tanks in the loft, strengthening the joists etc.

Try Boxt and be done with it.

But I echo piglet to get the pipes lead mains changed.

You can still get unpressurised boilers that use an feed and expansion tank. I have one, a Viessman Vitodens 100 Compact Regular boiler. It has a stainless steel heat exchanger, a long guarantee, and is so small it fits in a 400mm kitchen wall cabinet.

being a conventional boiler, it has hardly anything inside it to go wrong.

Pressurised boilers, and combi boilers, are always bigger because they have more stuff inside them.

Hi everyone, many thanks for the feedback so far. I have a bit more information now.

We've had British Gas over to provide a quote and they said that the reason we can't put the new boiler within the chimney breast where the old one is is because the space is too small. He recommended not putting the boiler and cylinder in the loft because he said we would need scaffolding for the required roof work and we would need it any time a repair needed to be made. They also said they don't put unvented cylinders in the attic due to their weight. In any case I'm not keen on pursuing that route anymore due to the extra cost to move the system into the attic.

BG did a water pressure test and confirmed we have sufficient pressure for an unvented system. BG has quoted almost £7k, similar to the independent.

We are about to do up our kitchen which is quite large and has a lot of unused space, therefore I think the best option would be to put both the boiler and cylinder there. The cylinder is currently in one of the bedrooms which is already a tiny room therefore it would be really useful to have the space back to use as a wardrobe.

The independent said that if we don't put everything in the attic, the quote would come down a fair bit due to the reduction in work. However he's very unresponsive to my emails and has limited availability so I don't think I'll go ahead with him. In addition, BG offer up to 4 years interest free credit, which seems well worth opting for the current high inflation meaning the cost to us in real terms will be much lower.

@PigletJohn I spoke to Thames Water and they asked me to first assess the pipes. I've taken a look and compared against information I found online and I believe they are copper pipes. They are connected with plastic connectors.

Would you recommend an unpressurised boiler over a pressurised one? Is the only different the pressure at which the water flows through the heating system? Our shower is quite low pressure so I'd be very happy with an increase in pressure.

The independent suggested the Greenstar 27i boiler which fits into a standard kitchen cupboard apparently, whereas BG quoted us for the Greenstar 4000 24kW, which is much bigger and I'm concerned won't be powerful enough (a bathroom, downstairs toilet, 9 radiators including a small one in the bathroom). The 27i seems like the better option to me but I can't find much information that helps me differentiate between the two options.

Is it worth getting BOXT out to quote too? Or shall I just moved forward with BG?

Also, with my kitchen installation I'm concerned about timings and what needs to go in first - I assume the boiler!

Another thing is that I'm now thinking of putting in wet underfloor heating in the kitchen to eliminate a very cold kitchen floor (concrete) and remove the large radiator from a wall that could be used for cupboard instead. Does the boiler need to be more powerful to accommodate this and would I need BG to assist with the set up or can my builder of all the connections after the boiler system has gone in?

Really struggling with all these different moving parts!

I made a diagram!!

I forgot to mention that the red rectangles are radiators.

BOXT don’t go out to do quotes - they quote remotely based on info you provided.

Ah ok thanks. It comes up with the same two boilers I've already been recommended, which is reassuring. The 4000 is the recommended one (due to popularity). The quote is £4.5k without cylinder and they don't seem to sell cylinders. I'd prefer to get everything done at once and in any case I'm not sure if a pressurised boiler would work with my existing water cylinder 🤔

I have just done this same job, including new radiators being fitted. 7k in London. I think you have had a fair price.

I have the same boiler as PigletJohn. Fitted in February and working flawlessly. Feel a sense of pride in picking the right one 🤣

Ours was specified and fitted by an ex BG engineer who went out on his own 5 years ago. We had the boiler, brand new pipe work to it, new flue and new 150l ideal unvented cylinder fitted in the airing cupboard. It fills the cupboard more than the old one but it’s not a problem. We’re using a fraction of the gas we used previously although it did take a while to get used to the fact there’s no room thermostat in our set up.

Done and dusted in 2 days for £4300

Thanks Jins, do you know why the engineer suggested the unpressurised boiler rather than a pressurised version?

@DIYamateur the set up was to try to replicate our previous all in one system set up so we needed a priority hot water boiler and a pressurised/unvented cylinder. Viessman had the correct pipe work built in and vaillant and Worcester Bosch would have needed extra work.

We also liked the fact that he’d fitted 25 in the last 12 months, everyone was happy with them and they are easy to work on. We have 12 years warranty on ours by paying £220 to extend by 5 years.

Our boiler had been condemned so we didn’t have the luxury of time but now that you’ve had a British Gas quote I’d ask a few independents in. A good engineer will ask you what you want to prioritise and design accordingly

I don't know any good reason not to fit a room stat, though I am aware a few people don't do it.