coozer
|
| posted on 7/2/14 at 07:02 PM |
|
|
Combi Boiler problem..
Calling all boiler engineers..
My Vokera is playing up, I think it can hear the British Gas adverts on TV atm and wants to retire..
Anyway, central heating pressure is falling off and I'm filling with water ever day now..
If i fill anything above 1 bar when it comes on the pressure runs just over 3 bar which in turns makes the outlet on the pressure relief valve a
little wet.. If I fill just under 1 bar it works OK for 2~3 days..
My immediate thoughts are a new pressure relief valve but the over 3 bar running pressure is more likely the cause.
So, my thoughts turn to the pressure vessel.. is it likely to not be absorbing the running pressure and causing the fault? I'll be checking that
tomorrow after I've worked out how to get the cover off...
I'm loath to shell out £2~3K on a new boiler when all the spongers around me are getting them fitted for nowt!
1972 V8 Jago
1980 Z750
|
|
|
|
|
David Jenkins
|
| posted on 7/2/14 at 07:21 PM |
|
|
With our old boiler (Baxi - just replaced) this used to happen when the diaphragm in the pressure vessel had split (for about the 8th or 9th time).
|
|
|
jacko
|
| posted on 7/2/14 at 07:21 PM |
|
|
Could you have a small leak in a radiator or pipe ? that would make it drop pressure
|
|
|
Wadders
|
| posted on 7/2/14 at 07:22 PM |
|
|
You have u2u 
|
|
|
r1_pete
|
| posted on 7/2/14 at 07:27 PM |
|
|
You can fit an external pressure vessel, not sure what's involved, but it can't be much more than capping the internal ones feed, and
teeing into the circuit somewhere.
There's a howto here
|
|
|
coozer
|
| posted on 7/2/14 at 07:37 PM |
|
|
quote:
Originally posted by jacko
Could you have a small leak in a radiator or pipe ? that would make it drop pressure
No leaks, that was the first thing I checked.
1972 V8 Jago
1980 Z750
|
|
|
JoelP
|
| posted on 7/2/14 at 07:38 PM |
|
|
A lack of air in your pressure vessel can cause those pressure fluctuations. Could drain the system fully to let air back in to it.
|
|
|
watsonpj
|
| posted on 7/2/14 at 07:38 PM |
|
|
Sounds like the pressure vessel has failed which is pretty comon (mines failed after 3 years). You can replace the internal ones but its a open the
boiler job (gas safe enginer). I just added an external one which is very easy and cost me about £60 all in. I could have done it cheaper but I put
one in twice as big as the original as some say that they last longer as the bladder has less stress which makes sense.
Loads of videos on line to do it but its really easy
Pete
|
|
|
samjc
|
| posted on 7/2/14 at 08:13 PM |
|
|
Youd be supprised on the price of a new boiler know, mine has 7 year warrenty and cost £840 with £250 to fit which i thort was steep seen as it was a
straight swap. Hope its a easy cheap fix to save shelling out tho.
|
|
|
coozer
|
| posted on 7/2/14 at 08:45 PM |
|
|
Right, I've got to the pressure vessel and its flat.. that is, theres no air in it. Also theres no water coming out of it, theres 0.5 bar on the
water side.
Just need to find something to pump it back up!
If I can fix it for the price of a bike pump then I'll be chuffed to bits!
Only device for inflation here atm is my 200l compressor... a bit overkill and cant get it into the kitchen
1972 V8 Jago
1980 Z750
|
|
|
watsonpj
|
| posted on 7/2/14 at 08:57 PM |
|
|
its probably the schrader valve failed, try pumping it up first to see if it holds but if not halfords sell the removaltooland the valves for about 3
quid.
|
|
|
woodster
|
| posted on 7/2/14 at 09:27 PM |
|
|
This kept happening on my combi , I'd fill it up every other day and then the pressure would just drop and the boiler wouldn't work, I
thought it must be a leak on the system , asked a plumber at work he said it could be an air lock so I went round the rads and I found one that was
cold at the bottom, after closing rad valves and forcing the air out of the system the problem was solved
|
|
|
