Correctly setting bypass valve

[willougs]

Hi all. Would appreciate some help from some experts. Several questions I'm afraid

1. I have a valve fitted in-line on the pipe from the bottom of my hot water cylinder coil and, whilst trying to find out what it did (I'm definately no expert), I messed with it. Now I'm not sure it's set correctly. It appears to be half-on, and speaking to a British Gas engineer, he said it was a bypass value and shouldn't be touched.

What is the easiest way for me to set this valve up to the correct position?

2. The cold water feed into the header tank in my loft is really really noisy - when someones taking a shower, the hissing noise of the tank filling is loud enough to be heard downstairs or to wake someone in the bedroom below. Can this be quietened?

3. I currently have a (ten year old?) ACL LP241 programmer and would like to change for a LP722. Is this possible? It is an easy DIY task?

4. Finally, I would be interested in getting 7x TRVs installed and would be appreciate it if someone could give me an idea of how much I'd be looking at to get them supplied and fitted

Many thanks in advance!
Steve
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Lynda, moderator

please read forum rule 9

 

[willougs]

3. I currently have a (ten year old?) ACL LP241 programmer and would like to change for a LP722. Is this possible? It is an easy DIY task?

Seems like this site answers this one:-

http://www.heatingcontrolsonline.co.uk/product_info.php?products_id=107

...assuming that the design of the newer LP722 fits with the design of an old LP241, it appears they share the same back plate - and therefore a 5 minute D.I.Y job to fit ??

Thanks
Steve

 

[ChrisR]

1. Never seen or thought of a really good answer! (That doesn't mean there isn't one though!) Many systems don't have a valve here. I daresay you've worked out that the idea is that the HW circuit doesnt "short circuit" the CH too much because that would more or less stop the heating working while the HW is heating.
You could set the valve so there's a 10degree drop across the HW coil when the boiler's hot and the water's cold and the CH is off, but the situation is so radically different when the heating's on, and/or the hw is warmer, that it's a bit hit and miss. Doesn't work as well as for a rad because it's a much bigger heat-sink.
My system doesn't have a valve at all; when the HW is on with the CH, the rads do heat but not much. The HW only takes 20 mins to heat from cold though, so I don't notice it. Quickest-possible HW is useful - time them separately with your new programmer.

If I had a valve I'd close it, then open by 1/3rd and test.

It will be interesting to see others' replies on this.

2.Noise - there are quieter valves, like Torbeck, and other better ones, and you could get some plastic pipe cut into the supply by the cistern to reduce noise coming down the supply pipe. Don't use a flexible coupling unless you use a very good one. Cheapie tap connectors have a habit of bursting.

3. Easy
4. TRV's cost between £5 and £20 say. Go for the better end if you want them to last more than a few years, and or the best control. It's the heads that fails though, so if you go cheap, buy a few spare ones. Labour - allow half a day. Plus say £20 for good quality inhibitor, assuming the system is drained.

 

[willougs]

Thanks ChrisR for your time.

To be honest I'm not 100% sure on the point of the tap on the bottom of the cylinder coil. Am I right in maybe thinking that the coil is on the same circuit as the radiators, and therefore whilst heating the water in the cylinder, the water going around that circuit will be cooled enough to reduce the heat of the rads? Therefore by sticking a tap on it, you are limiting the amount of water that gets 'cooled down'? Sorry for being a bit dumb.

Thanks for your replies to the others though. Very much appreciated and makes perfect sense. As a matter of curiosity, what's an "inhibitor'?

Thanks again,
Steve

ps. sorry mod, wasn't aware that rules stated I wasn't allowed to ask approx prices...