boiler losing water pressure

gordon029

Hi I have a Baxi wall hung condensing boiler about 3 years old.I noticed the guage on the front had gone down to zero and some of the rads were not heating fully. I called a plumber just before Christmas and he filled the system which brought the guage up to halfway but it is working its way back down . I have checked all the rads for any sign of leaking but nothing obvious so would appreciate any advice about what to do next as the plumber is gone away for holidays and I don't want the boiler to get damaged. Thank you for reading this and all help appreciated

Dtp1979

gordon029 wrote: »

Hi I have a Baxi wall hung condensing boiler about 3 years old.I noticed the guage on the front had gone down to zero and some of the rads were not heating fully. I called a plumber just before Christmas and he filled the system which brought the guage up to halfway but it is working its way back down . I have checked all the rads for any sign of leaking but nothing obvious so would appreciate any advice about what to do next as the plumber is gone away for holidays and I don't want the boiler to get damaged. Thank you for reading this and all help appreciated

There should be a small half inch pipe outside near the boiler. Is it dripping?

K.Flyer

If your Plumber has shown you how to top up the pressure on the system, bring it back up to approx 1.5 bar when cold, then get someone out to take a look at things after the break.
Don't be tempted to keep topping up the pressure for months on end as this will eventually do damage to your heating system.

gordon029

thank you both for your responses. I cant see the end of the half inch pipe so not sure if it is dripping. The boiler is currently running at between 2 and 3 on the guage.

greasepalm

sometimes finding the leak can be hard,go to every room and look at rads and pipe connections and check for leaks sometimes one can be lucky and is seen out in the open.

Dtp1979

gordon029 wrote: »

thank you both for your responses. I cant see the end of the half inch pipe so not sure if it is dripping. The boiler is currently running at between 2 and 3 on the guage.

Probably the prv and expansion vessel at fault

van_beano

Dtp1979 wrote: »

There should be a small half inch pipe outside near the boiler. Is it dripping?

Quick question on this point actually. I've the same issue as the OP, pressure gauge drops from 1 bar to nearly .25 bar or less every so often, I do add water to the system to bring it back to 1 bar, no visible leaks anywhere.

The boiler is on at the monent, heard water moving in it, so had a look outside at that pipe you are describing, mine is pointing towards a regular rainwater drain on the ground. There's drips coming out of it and steam. Also the other vent pipe up top above lower roof level where the steam comes out gushes out the odd splash of water sometimes.

As you can see I'm not too technical on the terms however are these things causing the pressure drop?

Dtp1979

van_beano wrote: »

Quick question on this point actually. I've the same issue as the OP, pressure gauge drops from 1 bar to nearly .25 bar or less every so often, I do add water to the system to bring it back to 1 bar, no visible leaks anywhere.

The boiler is on at the monent, heard water moving in it, so had a look outside at that pipe you are describing, mine is pointing towards a regular rainwater drain on the ground. There's drips coming out of it and steam. Also the other vent pipe up top above lower roof level where the steam comes out gushes out the odd splash of water sometimes.

As you can see I'm not too technical on the terms however are these things causing the pressure drop?

The pipe that's dripping water, is it copper or white plastic?

van_beano

Dtp1979 wrote: »

The pipe that's dripping water, is it copper or white plastic?

It's copper, pointing about 5 inches straight out from the wall, there is a plastic pipe attached at the end to direct any water into the drain.

There's another copper pipe coming out from the wall close to that other pipe, nothing seems to come out of that one though. It's a WB Greenstar 30 CDi Condensing gas boiler.

Dtp1979

van_beano wrote: »

It's copper, pointing about 5 inches straight out from the wall, there is a plastic pipe attached at the end to direct any water into the drain.

There's another copper pipe coming out from the wall close to that other pipe, nothing seems to come out of that one though. It's a WB Greenstar 30 CDi Condensing gas boiler.

It's hard to know but condensate pipe should never be copper. Best get it checked out or post a pic here of it

van_beano

Dtp1979 wrote: »

It's hard to know but condensate pipe should never be copper. Best get it checked out or post a pic here of it

Just took a pic there. The one on the right over the drain is where there was dripping earlier. It's actually plastic and not copper, sorry. The pipe on the left is metal, nothing visible comes out of that. Boiler is right behind that wall.

Dtp1979

Then I'd say your cylinder coil is leaking

Not a plumber!

My PRV recently let go, the cause was the expansion vessel failing. I changed it myself along with the auto vent, and the PRV. All of a sudden I'm having to top my system up every couple of days. The system when on would rise to 3bar, which unnerved me. I had a plumber out , who replaced the thermostat, due to the upper limit switch being faulty( water is so hot right now), after two weeks of looking for leaks ( none present) I finally found a hint that I should change my pressure gauge for a new one, whilst the pressure was down I checked the pressure in my NEW expansion vessel, I found that the manufacturer charge these up to about 5 bar, so I reduced the pressure to the recommended 1.5 bar( 15 psi). Now my system cold is holding at 1.5 bar and when hot at 2 bar, and holding steady. Just something else to try.

Dtp1979

I don’t know where you found a central heating expansion vessel that’s pre charged to 5 bar. I’ve never seen one anyway

Not a plumber!

This is my third one in twelve years, and I have had no trouble until this one. But then again, I'm finding out the hard way, plumbing is never straight forward.

jca

Not a plumber! wrote: »

This is my third one in twelve years, and I have had no trouble until this one. But then again, I'm finding out the hard way, plumbing is never straight forward.

Domestic plumbing isn't difficult. Heat source, circulation pump, pressure vessel, accurate pressure gauge on the system and the ability to follow logic and read should de-mystify most problems.

Dtp1979

jca wrote: »

Domestic plumbing isn't difficult. Heat source, circulation pump, pressure vessel, accurate pressure gauge on the system and the ability to follow logic and read should de-mystify most problems.

You would think. Unfortunatley not the case

Not a plumber!

MOD <snip> Totally irrelevant to OP. Stick to topic or don't post.