Boiler pressure fears

[gemcette]

Hi there forumites.
My boiler packed in on Xmas Eve, and I noticed that the pressure had dropped to zero. In the absence of a handy tap to twist to increase the pressure, I had to change all my plans over the festive season. Managed to get a boiler man round today who showed me where the screw was underneath the boiler to increase the pressure. He twisted it and set it at the recommended 1.5 and did say it would climb a little as the water inside the system got hotter. All good. - Not quite.

An hour or so after he left, the pressure climbed, and climbed, way over the 1.5 recommended mark and has now gone past the 3 and off the scale. I tried to call, but it seems their office closed at 6pm. I thought, maybe, he'd just let too much water in, so I've bled the radiators to the tune of 30 jugs of water or more. Still the pressure keeps going up. I'm now starting to panic a little.

Can anyone suggest what I might be able to do until tomorrow when I can get through to the office.

Best wishes and thanks,
Gina

 

[corgiman]

what boiler do you have?

 

[JohnD]

you've taken out 30 jugs of water and the pressure is still going up?

assuming you have turned the boiler off, it sounds like the filling loop has been left connected and has not been turned off tightly.

(excess pressure rise when hot has a different cause)

turn off the boiler and verify that the filling loop is tightly shut

 

[gemcette]

Valliant, but can't tell which model from the instructions. Shall go and examine the equipment

 

[corgiman]

the filling loop has not been closed properly

call your man back

 

[gemcette]

the filling loop has not been closed properly

call your man back

..the first thing I checked when it started going up was that it had been tightened. And I just get the property services answering machine. Should I just turn the boiler off at the mains and hope that nothing disasterous happens before morning?

Thanks for your help, by the way guys. I'm really starting to panic a bit here. There's not much space left on the dial. The pressure's already off the scale

 

[corgiman]

try turning the mains off and see if the pressure still rises?

 

[gemcette]

I've turned the water stop cock off and turned the boiler off at the wall. It hasn't dropped. Faulty guage? For the last few days it was on zero, now it's just gone wild

 

[JohnD]

turn on the kitchen tap for a moment

bleed the rads a bit more

 

[gemcette]

the pressure gauge drops a little each time I bleed the rads, and I turned the water back on and put the taps on, that also seemed to nudge it a little as well (only just back to the three mark, mind.) But wait a few minutes and it just all goes back off the scale again. Surely, if I've turned the water tight off at the mains (only a trickle coming out of the taps) the pressure shouldn't be building. Especially with the boiler turned off at the mains. I just don't understand.

Am I safe to sleep at home tonight? I have to say the guage off the scale just looks really frightening

 

[JohnD]

leave the mains off and the cold tap on

I think you have not got the mains tightly off

 

[gas4you]

I would hazard a guess at a Turbomax, with the slot type filling valves built in.

Check, as the others have said that both are fully closed. 90D across the flow.

It could be the exp vessel is flat, as this will make the pressure increase rapidly and then the prv will open and release the pressure and you are back to zero again.

Search FAQs on here on re-pressurising expansion valve for full instructions.

 

[gemcette]

Thanks gas4you for your kind and detailed response

I would hazard a guess at a Turbomax, with the slot type filling valves built in..

think you're right

Check, as the others have said that both are fully closed. 90D across the flow...

both? I double checked the one he showed me let the water in, and therefore increase the pressure. Which other one should I be checking?

It could be the exp vessel is flat, as this will make the pressure increase rapidly and then the prv will open and release the pressure and you are back to zero again..

I'm terribly sorry, but I don't know what exp vessel or prv means.

I'm happy to let the expert sort it out tomorrow, but just wanted to ensure the system didn't blow tonight.

 

[Stingray13]

I Wouldn't say this was a Vessel issue this does sound like part open filling loop if i remember rightly these are slotted keys (Or flat screwdriver).

Could be that there is some debris in the pipe i went to one six weeks ago that was doing this, they had had several people around and no joy i was there ages looking couldn't find a problem until i took the braided internal hose out, found a tiny amount of lime scale in the filling loop keeping it open even though it looked closed. (Took some mighty skill with a piece of solder to remove)

Call your person back and get them to have a look, the will probably have to replace the PRV as well depending on the quality of system water but they rarely seat properly anyway after use.