Plumbing in towel rail separately from the CH

[Lobster]

We have a heated towel rail in the bathroom which is plumbed in conventionally to the central heating, so it comes and goes off with all the rest of the radiators.

SWMBO has decreed that she would like it to work 365 days a year, so she has a nice warm towel to come out out of the shower to, which I believe is fairly common practice to arrange when towel rails are installed?

However, if I am to accede to the request I need to get my head round where the pipework needs changing.

System is as follows. Pipework to the gas-fired system boiler downstairs is two 2 22mm pipes flow and return, along with gas in and condensate out. The two 22mm pipes head upstairs and under the upstairs floor, and through the house to the unvented HW cylinder lives in the airing cupboard. Bathroom + towel rail is upstairs too, in the other direction. HW and CH are controlled independently.

So - am I right in thinking that I can simply run a pair of new pipes from my towel rail to intercept the two 22 mm pipes, in between boiler and HW tank; and then the towel rail would simply go on and off with the HW instead of with the CH?

Supplementary questions:

1. OK to run the new pipes in 10mm microbore (ie soldered direct to the 22mm pipes via T-adaptors) or would that screw things up? Whatever happens, it's not an easy route to run the new pipework, microbore or otherwise.

1. Would it be better or worse (from a long-term economy viewpoint) to fit an electric element to the towel rail in parallel with the wet system, and run that (off a time-switch) in the summer only?

Thanks David

[Owain]

Probably slightly worse from economy to run it off electric, but does your hot water system run whenever the shower does (which it woudln't if the shower was electric, f'r instance)

Why not use a push-button timer set to about an hour, so that Mrs Lobster can press the button before she slips into her bathrobe and goes in, the towel will warm up while Mrs Lobster is slathering her claws with whatever unguents Mrs Lobsters use in the shower, and the rail will stay warm for a while afterwards to dry the towel.

About =A330 from Elkay Energy Sense range

If Mrs L spends longer than an hour in the shower she'll come out to a cold towel, so an encouragement to her to use less hot water too.

Owain

[Roger Mills]

You don't say where the HW and CH pipes split, or what controls/valves etc. you've got.

I'm guessing that there's either a 3-port valve or 2 x 2-port valves in the airing cupboard - controlling the CH and HW circuits? Is the pump also there, or is it integral with the boiler? Either way, you need to take a feed for the bathroom rad from the flow pipe *after* the pump but *before* the valves. That way, the rad will be hot whenever either or both HW and CH circuits are active. You *may* be able to leave the bathroom rad's return pipe as it is - but check that this doesn't result in any reverse flow problems (for example, causing some other rads to get hot when only the HW is on).

[Lobster]

OK, the pump's downstairs, integral with the boiler, and yes there's a

3-port valve plumbed in upstairs, just above the HW cylinder.

Either way, you need to take a

So that sounds as if my plan above ("So - am I right in thinking...") is correct then!

You *may* be able to leave the bathroom rad's return

Doesn't sound as if it's worth risking that; if I have to find a way to get one new pipe through, then apart from making a couple more joints there's no more aggro in running the second pipe alongside it.

Anyone got any feedback on my 'supplementaries'? ;-)

Many thanks David

[David Hansen]

On Tue, 24 Nov 2009 22:45:52 +0000 someone who may be Lobster wrote this:-

Yes. You will probably find that you still need to have the balancing valve on the towel rail almost shut, otherwise most of the water will circulate through the towel rail rather than the radiators.

Depends on running hours, but in most circumstances better to heat from the boiler. In general electric elements are fitted for ease rather than reduced running costs.

[Roger Mills]

If you want to achieve more or less the same effect without needing any pipework changes, you might consider the following - which I used to do:

• Leave the bathroom rad(s) on the CH circuit

• In the winter, it/they will come on whenever the CH is on, which is sufficient

• In the summer (when only the HW is on) remove the actuator from the 3-way valve (but leave it connected electrically) and physically turn the wet bit of the valve to the mid position

• Turn off all radiators except those in bathroom(s).

• Then, whenever the HW is being heated (as determined by the timer and cylinder stat) the bathroom radiator(s) will also get hot.

[fred]

In article , Lobster writes

That's certainly the route I have followed, it's surprising how little power it takes to maintain a good temperature on a heated towel rail with towels on it. I have a half height rail with a 60W (I think) element in it and I cut the power in half with a power diode as it was just too hot.

If you chose a mechanical timer with continuous 15min segments on it then you can have it on full around the time you shower most often to dry wet towels then have it on at one segment in 3 or 4 to maintain a base heat during the day.

The bathroom heat is provided by separate rads so the rail is always on electric. Very effective and absolutely no hassle to install.

[Lobster]

That's actually a rather good thought, provided it would warm up enough during the time-course of the shower in order to do its stuff - what do you reckon? If not, I can see me being forced into changing the switch for a rocker, so the bloody thing would end up being switched on 24/7!

Hmm, some quite interesting stuff there!

Thanks David

[Pete Verdon]

How about a flow-switch on the shower water supply? They come in both

15mm and 22mm sizes, ready-fixed to a short length of copper pipe. Great for turning on things that need to come on with the shower, when the occupant is likely to forget. I use one for my anti-condensation extractor fan, since I share my house with two lodgers and would prefer not to worry about other people forgetting to turn it on.

Pete

[Owain]

Depends how hot the towel rail gets and how long Mrs L spends in the shower, but it should certainly take the chill off. If necessary just switch it on a little earlier - or even an hour earlier, and plunge it again when finished showering to dry, it will still only be on 2 hours not 24.

Owain

[Lobster]

Ah, but prime lobster-showering time is first thing in the morning; ie she crawls directly from bed to shower (and trust me - 'just taking the edge off' really wouldn't cut the mustard!). The alternative would be a preset 7-day timer I suppose; our weekday and weekday getting-up times being pretty fixed.

David

[Lobster]

Interesting idea...

What does the above step achieve - preventing all the CH pipes getting hot or something? If so why does the towel rail still get hot?

Thanks David

[Roger Mills]

In the summer, with the CH off, the actuator will keep the valve permanently in the HW-only position. Removing the actuator (and leaving it off) enables you to manually move the valve to the mid (HW+CH) position without any danger of the actuator moving it back again.

In this position, water will circulate round the radiators whenever the HW is being heated. That is why you need to turn off all radiators *except* those in bathroom(s) which you *want* to get hot.

[Owain]

That would work then. Or you could have a concealed 7-day timer for waking-up and a visible hour-timer for occasional occasions and visitors.

Owain

[Lobster]

Ah, OK. I think I'm missing something though: what's the difference between doing that, and turning off all the rads except the towel rail, and then controlling the CH (which in summer would then comprise just the towel rail) separately as normal (ie, just having it come on for a quick burst at shower time)?

Thanks David

[Roger Mills]

The difference is that it will then be controlled by the room stat - which may decide that it doesn't need to come on. OK, you can turn the stat up to max, so that it comes on for the whole timer period. But, with the HW demand satisfied, and the boiler firing just for the towel rail, there may not be enough flow to prevent the boiler from overheating.

With my method, the towel rail is controlled by the *cylinder* stat, and only comes on while the HW is actually being heated.

[Andrew Gabriel]

What about re-plumbing the shower's hot water feed through it? Probably not long enough to heat towels through unless it's a long shower.

[Roger Mills]

Also, the *only* time it would get hot would be when the shower is running - which isn't particularly useful!

[robgraham]

I think Mr Lobster has a problem here of his own making - it would seem quite clearly that Mrs Lobster expects him to pander to her every whim and wish, and in the past he has done so. I suspect there has been a bit of carelessness here in that the OP has in fact lead his better half to understand it *can* be done.

More fool, Mr Lobster - the first rule of anything that SWMBO requests is the much sucking in of air, ( viz. the local builder),and an indication of how difficult, how expensive and how long such a requirement will be to the detriment of all other tasks that have been set.

Will you youngsters never learn !! Rob