Combi Boiler Pressure too High

pennypincher3562

Hi

I've just noticed that the pressure on my combi boiler is too high - it's at 3.4 bar. I've turned the system off for now.

I will try and bleed the radiators when I get a radiator key (don't have.) Ideally, I'd like to try and avoid calling out an engineer if possible, as of course, they cost a fortune...

I was slightly worried, after reading on the internet that boilers can potentially explode due to, too high pressure. I've checked the filling loop, and I'm sure it is off.

Is turning the boiler off sufficient in this instance, or could the pressure keep rising and become dangerous?

Thanks
Pennypincher3562

Mr_Ted

:rotfl:Boilers DONT explode often these days they have safety devices

But you will need to get a professional in, as if you do a forum search you will see numerous posts that identify the possible causes, all of which cannot be legally DIY'd

cynicalgit_2

Sometimes over time the valve on either side of the filling loop can become leaky hence a gradual build up of pressure.
You could tighten up the valves and then drain some water out of the system.
However should the pressure continue to build then you will need to get a RGI in.
Boilers are designed to be failsafe, and you should notice excess water draining away to the outside of the property.

I_have_spoken

Is turning the boiler off sufficient in this instance

Yep. The pressure relieve valve will vent water/steam anyway, so no risk of explosion.

Your filling loop may be bypassing (unless you can physically remove it) or the expansion vessel needs to be re-pressurised or replaced.

macman

Once the PRV lifts, it often won't sat again properly and wil need replacing. So I'd make the minimal investment in a rad key sooner than later.
Out of interest, how have you been bleeding the rads up until now without one?
How do you know the filling loop is 100% closed unless you have disconnected it?

pennypincher3562

Hi

In response to macman, Ive never bled the radiators since I moved here 6 years ago. I can only presume the filling loop is closed, as its on the closed position, and I cant detect the sound of water going through it.

I bled all the radiators today. There did not appear to be air coming out of any of them, water came out more or less immediately.

After 'bleeding' the radiators, the pressure dropped as water had come out of them. This was only temporary, however, and within 10 mins the pressure was back up to 3.3.

I have called BG, and signed up for their plan which provides initial repair for 99 quid, and then cover for 21 a month.

Not sure if I've done the right thing, but it's the best I can come up with at moment!

Cheers
Pennypincher3562

pennypincher3562

Ps. With pressure sitting at 3.3 can't see any water coming out of overflow. However I reckon the boiler might be preventing more water from entering it.

Until the engineer arrives on Wednsday, I will leave the thing off...

espresso

Why didn't you simply remove the filling loop?

macman

If the pressure is going up that fast then you clearly have a considerable flow through the filling loop, even when you think the valve is closed. I'd have thought that the PVR should kick in with it at 3.3? Turn off the supply to the filling loop.
A new filling loop and valve is about a tenner and an easy DIY job to do-no need to pay BG £99 for that! A plumber would do it in about 15 minutes.

pennypincher3562

Hi macman

Thanks for the advice. Ill try and get out of the BG arrangement, I think iv got a 14 day cooling off period (i signed up for the cover plan.) I will phone a plumber that I know, and see if he can do something.

Thanks
Pennypincher3562

pennypincher3562

Hi Espresso

Thanks for your tip. I didn't remove the filling loop as I don't fully understand how it works.

I don't know how to turn off the flow of water to the loop, and was concerned I could end up with water all over the place...

Cheers
Pennypincher3562