Newly installed Procombi HE boiler loosing pressure daily

[brenc82]

HI, wondering if anyone can help

We are completely baffled to why our new boiler is loosing pressure so much- it can drop from 1.5 to zero in a day if the heating is off, or gradually lose the pressure over 2-3 days if the heating is in use intermititently throughout times in those days.

I have looked at the other posts regarding loss of pressure but struggling to find an answer that could relate to our problem.

1. There are no visible leaks (the boiler was installed in end of sept 2010) and we have had to top up the pressure so many times - im sure the amount of water would be visible by now. The pipes are in concrete floor as we live in a bungalow.

2. The boiler is only a few months old and should be no wear on the expansion vessel. wouldnt it be unusual to have to repressurise a new boiler manually with a pump??

We installed a new wall towel radiator to the bathroom, air in system seems to gather here and bleeds the most (due to it being the highest point in system? )

The boiler is a ProCombi 100HE, wonder if anyone has had any problems with this make of boiler??

Thanks in anticipation
Brenc82

 

[spm8]

first call out who ever fitted your boiler to sort it out

 

[Agile]

2. The boiler is only a few months old and should be no wear on the expansion vessel. wouldnt it be unusual to have to repressurise a new boiler manually with a pump??

We installed a new wall towel radiator to the bathroom, air in system seems to gather here and bleeds the most (due to it being the highest point in system? )

The boiler is a ProCombi 100HE, wonder if anyone has had any problems with this make of boiler??Thanks in anticipation

Brenc82

Its very unusual to have to repressurise with a pump! Do you have no mains water then?

The leak is almost certainly under the floor in the copncrete. Didn't the installer warn you of the risk of leaks in the floor?

Dailr topping up brings in new oxygen which rusts the inside fo the rads, This produces gas which may be why you have to bleed it often. Soon it will be so sludged up that you will need it power flushed.

Tony

 

[brenc82]

Tony - no i dont have to pressure with a pump! it was something i read on a posting on this forum and i said 'surely i wouldnt have to do that'.

Secondly, to get the pressure up to 1 bar, its takes over 5 litres, could this amount of water dissapear without a trace of damp in the floor after 3 months of topping up every other day? thats alot of water.

regards

 

[brenc82]

spm8 -


I have had the plumber out various occasions and still no answers........

regards

 

[Ray84]

i think firstly id go down the line of spm8.
Your installer should be able to help with this best as he should be able to rule out the expansion vessel and help look down a process of elimination with other areas of the system.
Though its unusual it may be that the expansion vessel is faulty/undersized for the size of system etc or as you suspect yourself its most likely due to a leak in the concrete floors unfortunatly.

You said the boiler was fitted in september. Was your previous system a sealed system with no pressure problems? did your installer convert it from an open system and leave the existing pipework in concrete floors?

Tonys hit the nail on the head though as eventually it will lead to bigger system problems and unnecessary costs to yourself and any system leak sealant you may come accross isnt going to be suitable for a leak of this size.

Ray

 

[brenc82]

thanks ray,

my plumber has been out 2 or 3 times, and im still none the wiser for it. he has no answers apart from assuming its a leak.

the previous boiler was not a sealed system, emersion, tanks in attic etc.

What pipework would there be in the floor apart from pipes leading to the rads and cold water feed that he could have left in?? everything that was made redundant was from the attic tanks.

would the water not be visible by now though if it leaked in flooring ? 4months, every 2 or 3 days ,thats nearing 270 litres

thanks

 

[Ray84]

i understand having to top up 5 litres everyday would make you think it should be an easy enough leak to find and you'd expect there to be signs i agree but if you go back to the basics my thinking is:

-if its lasting longer by keeping the heating on and drops quicker when off the heat is helping a fitting/joint to expand partially sealing a leak where as a straight leak in the pipework would keep a constant drop.
When the plumbers taken redundant pipework away he will of capped several bits of pipework especially with it being a combi change so i would double check everything yourself and not take his word for it. Even something you thinks a small sweat could account for it so everything must be bone dry(inc rad valves etc)

could some of the concrete be suspended with a pipe/fitting underneath it? say for a drain running outside?

Your probably aware that this leak could have existed since the old system was installed but you wernt aware due to the tanks keeping the water levels maintained or it could be due to the new pressure being put on the system?

If you think the boiler may still be an issue if you wanted to do a rough test on the vessel in the morning when cold and pressures at zero if you topup to 1bar and let each radiator fully heatup until the boiler cuts out re-check the gauge, if its anywhere near 3 that would put blame on the vessel.

Whats the size of the copper pipes going to the radiators is it 8,10,15 or 22mm?

Ray

 

[joe-90]

Didn't he carry out a pressure test before installation?

 

[brenc82]

thanks ray,

yeah the pressure is constant when the heating is on, its the intervals wher its switched off where it plummits.

yeah your right it may have existed on the old system, just trying to elliminate everything before having to start looking to repair ground pipes (not that i know where to start looking!). new pipes coming down the walls is not an option after the effort we'v gone to to replaster / decorate etc.

think the pipes are 22 and reduce to 15 where it tees off to rads (dont quote me though, i think thats what i remember seeing when we exposed some to puta towel rad on.

the pressure has never increased above 1.5, so guess the vesel is fine as

expected for a new boiler.

its so frustrating not knowing where to go with it after spending the money on what we thought would be an effiecient no hassle CH system.

thanks

 

[gigz]

How do you know you are putting 5 litres a day in ? As already said you must have a leak under the concrete and when you have the heating on it expands the pipes, this probably temporarily seals the leak, when it cools the pipes contract and start leaking again, the only real way of solving it is probably a re-pipe (possibly a full one) as unless you can isolate the leak it is all linked together somewhere.

 

[brenc82]

i timed how long its takes to get the pressure back up to 1bar using the filling loop, and then disconnected the filling loop and opened the tap up for the same time just under filling a 6 litre water bottle.

as ive said, im trying to elliminate everything first -

"yeah your right it may have existed on the old system, just trying to elliminate everything before having to start looking to repair ground pipes (not that i know where to start looking!)."

 

[spm8]

could try looking for leak with inferred temp sensor in concrete floor mite show up some differences

 

[steve32]

suggest you check out this company haven't used them myself but have heard good reports


Munters MCS - Leak Detection Services

www.munters.co.uk

Steve

 

[jj4091]

I'm not an expert but I would have thought you could rule out a leak in the rads & pipework simply by isolating at the valves under the boiler, then leaving switched off for 24 hours. If you still lose pressure it would seem to be a problem with the boiler.