HELP! Low pressure in my combi. Very worried!!!

[markandamie]

Hi, bear with me this is the first time ive posted a topic despite reading many and finding all very useful.

About 2 weeks ago my wife noticed the pressure had dropped on our Baxi 28 Duo Tec. It was installed 2 years ago. This happened a few months ago and I re-pressurised it and all was fine since then.

Over the next few days the pressure kept dropping and the error E119 (low pressure) was showing after about 7-8 hours.

We had a lady out from the company who installed the boiler and she stated it was the pressure sensor which had gunk on it. She fixed the problem and said it would be fine. We went away for Xmas for 5 days to come back and find the error being shown again.

Engineer (a different one from same company) came out and looked at the boiler and said there had to be a leak somewhere. No leaks could be found anywhere, not at any rads or through the ceiling. He said we might have to rip up the flooring in our lounge as the leak could be under there, or do the same in the upstairs, rip up floorboards. This horrified my wife and I as we have recently renovated the house doing a lo of the work ourselves (no plumbing mind!) and we would be devastated to rip up the wooden flooring we have laid in the lounge.

The following day a leak sealent was put into the system (as a last resort the man said) and we gave this a few days but still the pressure went down. It is gradually getting worse and knocks itself off with the error code showing after around 4-5 hours now.

We started to panic at this point thinking we ha no choice but to ruin the house. We called the building insurance.

An engineer from another company (to do with the building insurance) came out yesterday and after looking at the boiler for a short time said the Pressure Release Valve needed replacing and this was the problem. He said he was 99.9% sure this was the problem. He went to the back of the house and said he saw a drip from one of the outlets. He showed me the outlet but despite me looking a few times that day I could not see any drips or water coming from it. I am totally confused as to who to believe? We obviously really want this to be the problem as it means no ripping up of floorboards!!!

This evening I noticed a patch of water directly underneath the boiler and on looking up underneath I saw a drop of water drip but I could not see exactly where it came from. Ive not notcied this before over the past couple of weeks to be honest. Again confused!

We are battling with the insurance company to cover us for this as when the last emergency people came out they identified the condenser pipe at the rear of our home had not been fitted to building regs. This was installed by the company who'd been coming out telling me the floor was going to have to come up. They are coming tomorrow and I am going to explain to them the problem with the condenser pipe and hope they can sort something.

Any ideas on my problem would be gratefully received. Sorry if this post has made your eyes bleed but we've been unbelievably worried this past week or so and having read so many posts by you guys I thought id create one myself to see if anyone has any ideas.

Many thanks,

Mark H

 

[Mark Br]

Your condensate pipe is to discharge the condensed water from the flue gases away to (if internal) a waste pipe. Your condensate pipe will not be the cause of the boiler losing pressure.

Your Pressure release valve (PRV) is a safety device that if the pressure rises above 3 bar will release the pressure to the pipe outside. These can leak and can be a common the cause of the pressure losses. Tape a plastic bag around the pipe and see if it collects any water. If it doesn't then you're back to the drawing board.

Water under the boiler has to be coming from somewhere and this is worth exploring further.

 

[gasanstuff]

turn up to 1.5 bar and then turn off flow and return under boiler. pressure drop indicates leak in boiler . no pressure drop then leak from somewhere else!

 

[Agile]

You talk of the boiler faulting as if thats some inevitable action.

In reality its up to you to keep the pressure toped up until someone can find and fix the fault for you.

All you need is one competent engineer. You seem to have had people who are not very good.

It will probably result from a poor quality installation with a system that has not been cleaned properly.

Tony

 

[mmascarenhas]

Please help, am in same desperate position as OP, extremely worried.

Potterton Lynx 2 combi just had annual BG service after insurance renovation work in basement flat because of 'Escape of Water' damage from rising main. The system had been in full working order at time of investigation of leak which turned out to be rising main (not central heating related, which was tested at the time, good sustainable pressure, about 1.5 bar).

All radiators had been removed to repair rising damp/rot in walls and floors, one replaced in the bathroom, 21mm marine ply subfloor and expensive 21mm hardwood floor laid on top throughout flat.

During refitting of radiators, 2 had leaky valves which were fixed, but the system was not checked as fully working before contractors left or before the hardwood floor was laid by another company.

Within hours of the boiler service (after the floor was laid!!!), system cut out to 0 bar pressure, no heat no water, even on reset.

Second BG engineer refilled system at filling loop, replaced ISO valves which had slight dripping leak (left them in permanently open - vertical - position), fitted new ignition lead which had corroded, left the pressure at 1.5 bar, boiler cut out within hours.

Third engineer checked pressure release valve, dismantled it and flushed it through (no problem), replaced expansion vessel (which was full of black gunk), was going to change coupling loop but toby outside is seized in this perishing weather so couldn't isolate water supply in the flat.

B Gas say boiler is on 'restricted parts' but still serviceable within their Homecare 200 plan, even though third engineer got me to sign Safety Warning saying 'Boiler/Kitchen/Terminal Position' !!!! I assume that means it's becoming too expensive for them to service or find the fault, even though I've been paying up for 8 years and no call outs.

Kept an eye on the pressure gauge and it steadily rises to 2 bar then boiler shuts off and I have to reset every 40 minutes. All radiator valves at high, all bled, all dry at the valves (no leaks above floor), all heat up very quickly and no cold spots at bottom or top.

Last engineer suggested magiclean flush of system, or maybe there is a subfloor leak, maybe a floorboard nail or screw only slightly lodged in a pipe.

Question: are there any other things that could be going wrong in the boiler to go to high pressure, shut off, then reset light come on? If I don't reset, it eventually goes to Low Pressure warning light and 0 bar on gauge; same when it is switched off.

I seriously don't want to lift this floor and subfloor again to find possible leak, an insurance nightmare on top of an already 7 month insurance and botched jobs nightmare. There have been three main contractors on the job, two of whom have worked on the radiators and valves, but any one of many workers could have accidentally lodged a nail or screw sub floor into pipes, or it could be a slow leak at the new bathrooom radiator valves which were sectioned on sub floor.

Surely, this must come under Accidental Damage within the existing claim on Buildings Insurance which is already picking up the bill for the original repairs? There has been only one 5 minute visit from a Contract Manager at the beginning of stripping out work (no central heating pipes were replaced or lifted).

I can see this getting bogged down by the Loss Adjuster in legal claims about liability when all I want is my flat back with the working Central Heating System it had at the outset!!!

Please tell me it might still be the boiler. Thanks, and sorry for long post.

 

[markandamie]

Thanks to Agile Mark and Gasanstuff, apologies to other person but need as much help with the prob I posted as possible.

Agile, I have been repressurising the system on a dailly basis (be bloody cold otherwise in my house and totally agree with you in that some of the engineers are not competent.

Gasanstuff, how do I turn pressure upto 1.5 and turn of the flow, I know how to repressurise the system but that's about it to be honest, any ideas would be great!

Thanks once again to all, at least your not all saying rip up the floorboards!

Many thanks,

Mark H

 

[Steve69the69Gas]

OP look under the boiler front at the pipes from the bolier, the 2 large ones 22mm will be flow and return to your CH system. There may be a 3rd large one in the middlish - ignore this - it will be the gas pipe.
On the 2 identified, hopefully they will have a valve on each near to the boiler, turn these to a horizontal position to isolate the boiler. Switch off any call for heating.
But do you wanna mess with it in this weather?

 

[markandamie]

Cheers Steve, v good point about the weather, woke up in middle of the night when boiler turned itself off and could see my breath so probably not going to mess with it today!

 

[markandamie]

Just had an supervisor out from ompany who installed boiler. He tells me my condenser pipe does meet building regs and the engineer who said it didnt should have looked at the installation book! Who to believe? Confused again.

He agrees it could be the prv but doesnt think it is as id be losing more water. He's arranged someone to come out Friday to fit a prv. Fingers crossed itll work otherwise back to the drawing board and the possibility of my new floor having to come up.

Cheers guys for all your help,

Mark H

 

[Agile]

Second BG engineer refilled system at filling loop, replaced ISO valves which had slight dripping leak (left them in permanently open - vertical - position), fitted new ignition lead which had corroded, left the pressure at 1.5 bar, boiler cut out within hours.

Newgas, remember my posting about that lead? I wonder...???

Mascaras, you should not start your own posting in the middle of someone elses!

Copy it into a new topic and we will see if we can help you.

Tony

 

[mmascarenhas]

Apologies. Sincerely, didn't mean to hijack someone's thread, just thought we were going through same misery.

Will start new topic and hope someone can help. Thanks.