Switching towel rails to central heating instead of hot water

oniongirl

In our current house, and the house before, the towel rails are/were hooked up to the same feed as the hot water tank, so they're only warm when the hot water is on. When we moved in, the previous occupants had the hot water turned on 24/7 so the rooms were always toasty, but when bills started going up I experimented and found it was considerably cheaper to only have it on for 1.5 hours a day doing a full heat of the tank, before we wake up, and that sees us through, as there's only 2 of us.

That means that the downstairs loo, family bathroom and ensuite are all pretty chilly, not least because towel rails are not designed to heat a room (don't get me started).

Does anyone know if it would be an easy switch (for a plumber) to hook the rails up to the heating instead of the hot water? Would it just be a case of making the switch near the boiler, or would new pipes need to be run so they were fed on the same circuit as the other rads?

Finding a plumber is proving tricky, so I thought I'd ask the knowledgeable folk on these forums before going through any more heartache of people not turning up. Also I'd feel a bit more confident discussing what was needed if...you know, I knew what was needed.

ThisIsWeird

It all depends on how it's plumbed, the pipe runs, and how close the bathroom rad pipes are to a suitable CH 'flow' pipe. But I'd guess pretty straightforward.
I'm guessing that the three bathrooms are all plumbed together, and will have a single common source, possibly from the airing cupboard. That would make it simple to disconnect the 'flow' from there, where I presume it's currently being supplied from the DHW.  The 'returns' are common to both CH and DHW, so that pipe remains connected. So in theory all that would then be required is to have the 3 shared bathroom flows tapped into a CH flow, wherever it's simplest, and there's bound to be a number of options there.
But you won't know until you have a plumber in to look.

Descrabled

I assume that a system boiler is installed with one electrically actuated valve diverting the boiler circulating water to the central heating radiators and a second electcally actuated valve diverting the boiler circulating water to the coil in the hot water cylinder.

I fail to understand why anyone would plumb a towel rail onto the cylinder coil feed.

I've lived in houses with system boilers and they can be very efficient because they don't have to meet the very high heat output of instant hot water. I agree with you that heated towel rails are a silly way to heat bathrooms and I've always had bathrooms that were heated with radiators.

Modern hot water cylinders have good insulation and are very efficient stores of hot water and once they're up to temperature (60 C) then the cylinder thermostat signals for the electrically actuated valve to shut off the boiler water feed to the cylinder coil. I always ran my hot water cylinder heating on 24 hours a day because it only lost significant heat when hot water was being used. Putting on timer made little difference to the amount of gas used. Please confirm you have a thermostat fitted to your cylinder.

The extra energy used by having the hot water cylinder on all the time must be the amount of heat being used by the towel rails heating the bathrooms. So if you have the towel rails changed onto the radiator circulation system then your energy consumption will increase again.

The best way of saving money on your heating system is not heating one or more rooms. If you heat your bathrooms using towel rails or radiators then it'll cost more.

You need to find the two diverter valves and the feed(s) to the towel rails. Then you have an idea how easy or difficult it will be to change the plumbing.

ThisIsWeird

If you'd like to take some photos of your airing cupboard, OnionGirl, then we can try and locate the pipes in question. 

Rodders53

It could be possible with a bit of replumbing to create a new zone with an extra zone valve and additional controls (such as the smart Drayton Wiser 3).

1/ Radiators CH
2/ Towel rails
3/ HW Cylinder

That will allow the bathrooms to be heated as often as desired, including in the Summer when the main radiators are not wanted/needed.

You will need a decent Plumber to advise and do the work whatever you choose. 

Section62

Descrabled said:

I fail to understand why anyone would plumb a towel rail onto the cylinder coil feed.

Because they want the towel rails to come on every day, to warm the towels if not the room, and many people did (or do) turn the central heating off completely in the summer months.  Ideally the towel rails would have been on their own circuit, but if it were a choice of having the towel rails heated only when the CH was on, or having them heated every day, then the latter would probably be the most popular one.

In some cases this may also be a hangover from the days where the CH was pumped, but the hot water was on a thermosyphon arrangement.  As the bathroom was typically next to the bathroom it was relatively simple to plumb the bathroom radiator/towel rail as an extension of the thermosyphon.

If the towel rail/radiator was on a thermosyphon arrangement and the occupier didn't want or need the towel rail/radiator to come on then it was simple enough to turn off the valve on just that towel rail/radiator.

John_the_Boy

They might be able to plumb it so they come on from hot water and heating. That's what we have and it is ideal, for us at least.

ThisIsWeird

We look forward to a pic of OnionGirl's airing cupboard!

victor2

Our old gravity fed HW/Heating system had the bathroom radiator on the HW tank feed, but it was next to the airing cupboard with hot water tank in it (only have one bathroom). When we had the boiler changed to a combi, it was necessary to replumb that radiator, but we had it changed to a dual fuel one, so it could be electric or fed of the CH water. Smart switch on the electric feed to it, so we can have it on a timed basis in the summer.

Probably not a Money Saving solution unless you're having radiators replaced anyway though.

Albermarle

victor2 said:

Our old gravity fed HW/Heating system had the bathroom radiator on the HW tank feed, but it was next to the airing cupboard with hot water tank in it (only have one bathroom). When we had the boiler changed to a combi, it was necessary to replumb that radiator, but we had it changed to a dual fuel one, so it could be electric or fed of the CH water. Smart switch on the electric feed to it, so we can have it on a timed basis in the summer.

Probably not a Money Saving solution unless you're having radiators replaced anyway though.

When we had a new bathroom, we had similar fitted. I think in nearly 3 years, we have used the electric heating about four times ( twice when the boiler was not working) .
If it is cold the CH is on anyway, if it is warm no need to heat it. So do not find it that much use really.

victor2

Albermarle said:

victor2 said:

Our old gravity fed HW/Heating system had the bathroom radiator on the HW tank feed, but it was next to the airing cupboard with hot water tank in it (only have one bathroom). When we had the boiler changed to a combi, it was necessary to replumb that radiator, but we had it changed to a dual fuel one, so it could be electric or fed of the CH water. Smart switch on the electric feed to it, so we can have it on a timed basis in the summer.

Probably not a Money Saving solution unless you're having radiators replaced anyway though.

When we had a new bathroom, we had similar fitted. I think in nearly 3 years, we have used the electric heating about four times ( twice when the boiler was not working) .
If it is cold the CH is on anyway, if it is warm no need to heat it. So do not find it that much use really.

Must admit we rarely use ours on electric. But it is a heated towel rail more than a radiator, so does have its uses in the spring or autumn more than the summer. I must have blinked and missed this summer!