New Heating System

[imdad]

Hi all,

In a nutshell, we have just moved into a 4-bed detached house built in the late 80s.

Currently it has a very small hot water cylinder with a traditional system in place

• loft water tanks etc.

The radiators are all shot and the shower water pressure is terrible. Ironically, the mains water pressure is really good as are the rest of the hot water outlets.

The house is not insulated well so we’re getting that sorted now too.

We’re in the process of getting quotes for new central heating with larger combi boiler but one chap has asked have I thought about going all electric?

I hadn’t but he outlined the benefits:

• more attractive than pipes
• silent operation (no gurgling water)
• powerful pressures hot water tank
• control each room temp

The only downside I can see is running costs but he has mentioned it won’t be long and solar panels will be affordable and account for most of the running costs?

As you can tell, I have no idea? I thought I’d ask if anyone is all electric, what type of running costs per month do you pay, if you
Don’t mind sharing.

Thanks

Why do you say your Glow Worm Flexicom 18hx won't work?

Apparently it’s a heat only that won’t work at pressure? The pressurised tank is at pressure. Forgive my complete lack of understanding. I am more than likely wrong 😂

it's not actually correct. A heat only boiler sends water up the pipes as instructed by thermostat and timer. It neither knows nor cares where that heat is going.

(Actually a combi can do the same, it doesn't know if it is heating a radiator or a cylinder.)

if your boiler is unvented, it will need a small feed and expansion tank, higher than the highest radiator in the house, typically in the loft (some can be converted to unvented).

The water circulating from the boiler does not mix with the tapwater in the cylinder, and is does not matter if they are at different pressures.

Some plumbers are not qualified to work on unvented cylinders (yes, there is a qualification, and it is legally required).

I agree there is no point in scrapping an existing boiler that is in good working order, or is repairable. Yours is a condensing model, so pretty efficient.

The nightmare continues. The plumber also stated that there is no possible way of getting hot water to the proposed second bathroom (with separate shower) that we would like to add upstairs with our current system.

We are trying to save money where possible but the following problems remain:

• all radiators are terrible- old and do not give heat out. The valves all need replacing! One plumber said it will be sludge!
• we often run out of hot water. We think our cylinder is 80ltr only
• the shower - it’s TERRIBLE!

Do I need to pay thousands for a complete new system on a combi boiler?

Any help really appreciate.

P.S - I have attached a awful sketch to show The system set-up currently .

I can't see why an unvented cylinder wouldn't work.

How old is your plumber?

I would listen to Piglet John. His advice is very sound.

If it is a four bedroom house and the radiators are very old and tired...then I would seriously consider looking to replace the whole system, ie new radiators and especially the piping if this can be done reasonably easily. Definitely go for an unvented cylinder if the pressure is good. Don't consider a combi for a four bed house. We changed ours in each room every time we wanted a new carpet so the pipes could be moved as the new radiators were a lot smaller

I would also seriously consider changing the boiler at some point as well. We hung on with our glowworm boiler and kept having it fixed every 12-18 months as it had a design flaw. What tipped me over the edge was I was paying £300 a year to British Gas for a service contract and their service got so bad they wouldn't come out for minimum 1 week sometimes 2. Spoke to local plumber man and new Valiant Boiler fitted on the basis he will service it and deal with any problems (although it has an 8 year warranty from Valiant). Fab boiler (virtually silent) but what has been amazing has been the immediate crash south in the gas bills...circa 30% reduction in KW usage despite it having been at least as cold as last year

We have just moved here but we thinks it is 2013/2014. It’s been serviced yearly as it’s been a rental house since we purchased it a few weeks ago.

Would a pump of some sort work to increase shower pressure in both the downstairs (existing bathroom) and the (about to be added) upstairs bathroom.

The big saving in gas comes when you change from an old iron boiler to a modern condensing one. Your existing boiler is already a condensor. You can save a bit more by improving the controls and insulation, especially TRVs.

You will also want a magnetic system filter to capture circulating sludge and sediment, though the existing sludge will need to be cleaned out. The filter is only about £100 plus fitting, so an easy decision.

But I think your immediate problem is hot water. And I think an unvented cylinder is your solution. You may need to renew some of the pipework.

Ok, thanks.

I’ll get some quotes for the following options:

1. An upgrade to the water cylinder to an invented, larger cylinder. Replace the radiators and clean out the current system

1. As above but with a new boiler

1. Cost of a good combi boiler but with a good flow rate so that shower will be of decent quality. Obviously, we will need to coordinate shower times during busy times!

We have been offered, potentially, a few new boiler with a home eco grant but we would need to have wall insulation installed; I am a little nervous about the downsides to it so will probably leave it and pay for the boiler myself.

Thanks for your help.

We have had some quotes - for a new Ideal 35 boiler (14.5 ltr of hot water output) - apparently to have a good, strong shower. Without replacing the radiators, prices are between £5.5-8k.

Does this seem fair? I thought it would be much less. All have said that doesn’t include radiators or TRVs! This is extra.

I’m really shocked at the price to be honest. I am seriously considering other options such as upgrading what I have.

One plumber said that:

The boiler is working fine and is already efficient. He has suggested a add a larger cylinder as we run out of hot water too quickly, fit a pump which will increase shower pressure (terrible now) and ensure that when we install a second bathroom upstairs, hot water can reach there easily to run a shower too? He has also said that chemically flushing the Microbore pipes (8mm) and swapping new radiators and TRVs will massively improve the situation.

Would this sound like a cheaper but decent upgrade?

have you measured the flow of water from your incoming watermain?

oh yes, 12lpm in the kitchen.

If you enlarge some of the internal pipes, from the internal stopcock to a new unvented cylinder and the bathtap (and fit a new full-bore stopcock) to 22mm copper, I think you will get a decent HW flow. You can improve it dramatically if you run a new 25mm or 32mm plastic pipe out to the main.

Look at your internal stopcock, and the one in the pavement outside (might be integral to a water meter). Can you see the pipes? Are they blue plastic, black plastic, copper, iron or lead? are they as thick as your finger or as thick as a banana?

The moment you start having any plumbing done, get a Magnaclean or similar fitted on the circulation return to your boiler, and have a chemical clean. microbore is not very good for flushing but this will catch some of the sludge and prevent more building up.

bale out the mud from your F&E tank first to prevent it running down into the pipework.

... I think you will get a decent HW flow

...and no need for a pump

Hi PigletJohn and others,

We have now had three plumbers with very different suggestions and option. To be honest, we’re a little confused.

Plumber 1 - fit a combi and new radiators among sure that there are no leaks to new radiators and valves once pressurised £6500

Plumber 2 - suggested we keep the heating as a non pressurised system and replace radiators and valves. Install a pressurised hot water cylinder 250l and complete all work - about £4500/5000

Plumber 3 - has simply said he can’t seem the point in spending thousands. He has said that we should swap old radiators for new with new valves, swap 80ltr cylinder for larger 250- keep it unvented though. Install a newer quiet type pump that will serve the pump and the hot water feed to the new bathroom upstairs - £1500

What are your thoughts?

Thanks all. We are so confused!

I'm not keen on pumps and would prefer an unvented cylinder with bigger pipes to improve the flow.

But the cost difference between (2) and (3) is rather large.

I'd go for (2) and get it over with.

Is plumber (3) an older person?