HTC U12 Plus review: Hands-on
If there are any plumbers who could answer this I would be grateful.
I have a problem with my central heating system that has been like this for years. In order to run the central heating I have to have my hot water switched on. It is a 13 year old conventional boiler (potterton) and gets serviced every year. I have just had a new central heating pump and electric divertor valve replaced on a desperate fault but the problem still persists. I have mentioned this to the british gas engineers who conduct the service but none of them get stuck into the problem. Thanks in advance
I don't profess to know the answer but I sure as hell know that British Gas need a good kick up the arse.
You have been paying them to maintain your system for years and they still have not fixed it!!!!!
First guess if doing it for years is that it is not wired correctly, does your controller give the option of CH only.
I think you will find this is quite normal. I've asked a couple of CH guys in the past and they've said it is quite normal (they had a "name" for it, but I can't recall).
I have a Drayton Tempus Seven 7 day Programmer (quite a number of years old now, not a new fangled thing, but still with an LCD display). It has two settings (adjusted by a plug in bridge on the back of the unit):
CH & HW switch together (i.e. the bridge is in place). SO if either CH or HW is switched on, the other is on as well.
CH & HW (supposedly) switch separately. It works that way if just HW switched on. But if CH switched on the HW always comes on (there must be an internal relay that forces this).
It may be that more modern programmers don't enforce this, but I think it is just the way that it used to be. It might go back to times when the HW used to be gravity fed (no pump to HW cylinder and possibly no cylinder thermostat), and so the very fact of the CH being on meant that HW would get heated regardless (you could not stop it) and the programmers followed suit.
BTW, just 'cos I'm saying it is "normal" doesn't mean I think it is good!
Suggest you ask your question on a site like diynot.com (in the CH / plumbing sections)
You say that you have had a new "diverter valve" fitted this is different to a "mid-position" which will either close off the HW port and send the flow through to the CH or the if the cylinder stat is calling and not the CH thermostat the CH port would be closed and flow to HW cylinder, if of course both stats are calling the plunger or ball will rest in the midway position allowing the flow through both ports until either one or both stats are satisfied
If your system has been upgraded from gravity HW and pumped CH to a 3 port "diverter valve" or it was fitted from new with a "diverted valve" it is working correctly , you should not change the bridge as you call it in the system programmer the diverter valve is working correctly in that when you put both on on the programmer the HW will be satisfied first before the CH valve changes to CH. And in the summer/spring you flick off the CH on the programmer.
62 is about the right temp for the cylinder stat any higher if you are in a hard water area the cylinder will fill up with chalk.
My old (27yrs - changed last year) Potterton system was like that because it only had a two way valve and the plumbing to suit.
could set to HW only in summer but winter was HW and CH
No tank stat so water temp regulated by stat in boiler. CH temp was controlled by room stat that shut the valve to the rads when rooms warm enough.
sdave019trong text Does your controller give the option of CH only or not?
Not me intending to shout, something to do with the site formatting, anyway can you also confirm that the new valve you had fitted is 3port i.e. it has 3 pipes connected to it.
Thanks for all your help guys..I am pretty sure the 3 way diverter valve is working correctly as I can see it changing state and this leaves it with the wiring...With the wiring diagrams supplied on here I am going to check it for errors and possibly a cross short. The controller does has the option for CH only but it has been like this since the house was built 13 year ago and the system installed by the house builder.
I will let you know how it goes....thanks again :)
This thread is now locked and can not be replied to.