I have a potterton 50el boiler that powers my central heating and hot water. It is fully pumped and (I believe) a sealed system. The hot water is stored in a seperate hot water cylinder in the upstairs bathroom and the boiler is directly below this in the kitchen.

both heating and hot water have been working well since I moved in in November but for the last few days I have had problems with the hot water. Initially I could not get the hot water to come on without the heating and now the hot water does not function at all. The boiler shows no signs of life at all when the hot water is called for! However, the central heating still works with no problems.

If anyone can help with this at all I would really appreciate it!

Jade, April 2007

Hi Hi-spec,

Thanks for all your help.

It turned out to be a faulty microswitch in the powerhead of the hot water zone valve. I replaced the head and now I have both heating and hot water, yay :)

Thanks again.

Regards,

Jade, May 2007

you said before the plumber mentioned the wiring is all wrong maybe a good idea to get a elecy to check wiring.
if all the connections are nice and tight and you've checked stat, pumps working, and valve is ok can only be wiring. or programmer

hi-spec plumbing, April 2007

Hi Hi-spec,

I am pretty sure its not the cylinder thermostat. I short-circuited it and still got no response from the boiler....

I thought it may be the electronic control panel, so I disconnected it and short-circuited the back plate connections. This fired up the boiler when I connected the central heating connections but again nothing with the hot water...

So, I have run out of ideas again. Is there anything else you can suggest that may be causing the problem???

I am in Ladywell (nr. Lewisham), so probably a bit far for ypu to come all that way.. Roughly how much should a reputable plumber charge me to diagnose the problem? or maybe I need an electrician, seeing as how my boiler still works fine for central heating?

Thanks again for all your advice.

Regards,

Jade, April 2007

what part of s.e. london, im in southend.
it sounds like a faulty cylinder stat.
try moving the dial on the front it may be sticking.
but to test stat you need a elecy meter.

hi-spec plumbing, April 2007

Hi,

The boiler does try to start when I push the lever across quickly and as far as I can tell the boiler thermostat contact moves freely, however, no manipulation of the thermostat triggers the boiler to fire when hot water is called for....

Anything else I can check?

Thanks Again.

(South East London).

Jade, April 2007

if the motor is faulty and it still don't work when you push lever across by hand its not the motor because all that does is move the lever.
switch to water and push the lever across quick and listern if you hear the boiler try to start it may be that its not making the contacts.
also look on your copper cylinder in the airing cupboard there should be a stat 1/4 of the way up the cylinder, that is your hot water stat and that may be stuck, remove that from the cylinder and see if the contact on the back is moving freeley
if thats not calling for heat it won't switch boiler on.

hi-spec plumbing, April 2007

what part of london

hi-spec plumbing, April 2007

Hi Hi-spec, Hi Ray,

Thanks again for your advice.... but i still have this problem.

I have been away for the past week, staying with friends who have plenty of hot water :) so my apologies for not getting back to you sooner. I finally got a plumber round, but to no avail. He pointed out that my boiler has been wired up insanely (boiler set to fully pumped, control panel set and wired for gravity fed, none of the boiler wiring even looks close to the diagrams in the manual!). He didnt actually do anything as far as I could tell, and then suggested that I replace the whole thing..... I am not too happy with that idea as my boiler was working before!

Now, following your advice, I determined which valves feed the heating and hot water. The heating valve works fine (I cant see it move but the lever goes loose when the heating is on and the heating still works as ever). The hot water valve does not appear to function...

When heating and hot water are called for the boiler fires for the heating and, if i push the hot water valve open using the lever, hot water is also produced. Unfortunately, when i call for hot water alone (without heating) the boiler still doesnt fire regardless of whether the valve is open or closed? Any ideas?

I think that this might mean the motor is faulty as you both suggest, however, I am worried that it may also indicate that even with a new motor my hot water may not fire without my central heating being on?

Any further advice would be warmly received. I would also appreciate it if you could advise me as to where i might be able to aquire a synchron motor and how easy it would be to replace.

Also, as your remote plumbing actually seems more effective than that of the guy who came round.... are you by any chance based in london?

Thanks again for all the help :)

Jade, April 2007

there is a zone valve for hot water and heating. its a s plan system.

hi-spec plumbing, April 2007

THERE MAY BE A 'ZONE VALVE' FOR THE HOT WATER THE LITTLE SYNCRON MOTOR MAY BE FAULTY

RAY, April 2007

looked at your pics, on the side of them boxs is a lever that you can push across, the lever is on a spring so you can feel the tension on them, but when the valve inside is open the lever will be loose no tension. if you can stand looking at the boxs and put your heating on and you'll see the lever on one of the boxs move across, that tells you what one is heating and the pipe will get hot on both sides of box.
now turn heating back off and put water on the lever on the other box should move, if it doesn't push it across with your finger and it should clip into a groove in the silver casing, your boiler should fire up then when you turn water off lever will go back again. push the lever back & fourth a few times it may be sticking. then turn water on again it should start up on its own.


if when water turned on and lever doesn't move on its own but fires up when you push lever across, its poss that the motor inside is faulty and there only cheap about £10.00.


give that ago let us know what happens.

hi-spec plumbing, April 2007

Hi hi-spec plumbing,

Thanks for answering my plea for help so quickly!

In answer to your questions, the hot water fails to function with both timed and constant settings. There wasnt a pump or valves near my hot water cylinder but I opened up the wooden box above the boiler and I think I found what you are refering to. There is a pump and two (honeywell) square boxes attached to the pipes, which I assume are the valves. I took some digital photos and uploaded them on yahoo so you can see for yourself.

http://uk.pg.photos.yahoo.com/ph/lightmyshka/album?.dir=/c80fscd&.src=ph&.tok=ph.3hlGBy4vCqHAe

Thanks a bundle for your interest in my hot water problem. I am looking forward to any advice you may be able to offer me.

Hope to hear from you soon.

Sincerely,

Jade

p.s I failed to mention in my previous message that it is a potterton PROFILE 50el, just in case that helps at all.

Jade, April 2007

is the hot water on the programmer on timed or constant. ?

in your cupboard where your hot water cylinder is look for the pump in the pipework, after the pump is a square box valve have you got one valve or two ?

hi-spec plumbing, April 2007