combi valiant VCW T3W-D

[springsteen]

Hi I have the above combi, I know its old,however has done me pround.It loses pressure all the time,and I have to refill it everyday,often more then once a day.I'm sure its a leak of somesort,checked all the rads.,there seems to be a slight leak from one of the pipes into the bolier,and the hot water won't come on,unless the boiler is filled and the heating put on...any ideas,or has the bolier had it.

cheers.

[steve07951]

you defenetely have a leak thats the only way to loose pressure on a closed system u need to fix that first of all if u get a new boiler it will stil loose pressure. the reason the hot water only works when the heating is on is that the boiler is still trying to heat the rads the reason for this that the diaphram is most likley nackerd eg got a hole in .these can be replaced a plumber will charge about £70 to do it .but if its an old boiler a would change it for a condensing boiler they are about £400 but well worth it

[Realist]

Try changing the diaphram first and solve the leak, if that does not work then call a plumber and or change the combi.

Laters

[tubbiescooter]

if you do by a new boiler don't get a cheap one for £400 - 500 go for mid range around 700 - 850 ish i can reccomend either a broag remeha avanta around £700 or a worcs 24 greenstar 750 ish but if you got the cash spare buy a valiant again

[davex]

H'i,
On reading your post, the leak you have is highly unlikely to be sufficient enough to warranty the need for topping up your boiler every day, You would need to lose about 3 to 4 pints or more before the need for a top up.
So unless you are losing that amount, i would start looking at the expansion vessel, situated at the back of the boiler.
The easiest way to check this is after setting the boiler to the recommended pressure, switch on the heating, and observe if the pressure rises to around 2 and 3/4 to 3 bar. If it does, look outside your premises, at the pressure release pipe from the boiler, and see if it is letting water out. This will explain the loss of pressure from your system.
It may just need recharging to the recommended psi ( you will find this in the installation, and user's manual ).
To do this you will need a bike pump, and a pressure gauge.
You will find the valve on the vessel at the back, and usually on top of the vessel.
If after you have done this, there is water present at the valve, or it won't pressurise, then you need to replace it.
This is usually done by disregarding and blanking off the existing vessel, and replacing it with a new one, situated externally, and as close to the boiler as possible. It is then connected into the return pipe to the boiler.
I usually charge around £90 pound for this work, including parts, vat, and labour.
I hope this as been of some help to you, and has solved your problem. Good look.
Davex.