Arghhh-Boiler Probs

[daparojo]

I have a combi boiler which is 9years old, to which I was loosing about 0.8 bar pressure over 1 to 2 months, i.e. it went from 1 bar to 0.2 bar, but nothing less. It really didn't get that low for my boiler to enter lockdown mode.
I am on BG cover, and have been out many times to try and resolve the problem, fixing leaky valves, repressurising the air in the vessel etc. Still the same problem. There were no visibile signs of any leaks from the upstairs, but couldn't really see downstairs as the pipework runs under the floor boards.
Fast forward to the present, they fitted a new expansion vessel outside the boiler last week, put leak seal into the system and refilled the system to 1.5 bar. Everything seemes ok til last night. Boiler had zero pressure and entered lockdown mode. No leaks from the outside vessell, nothing from the pipe outside. Refilled the system to 1 bar about 9pm last night,this morning, it's back on zero and in lockdow - again no visible signs of any leaks. BG are coming back to look at this - this will be their 5th attempt to solve it the pressure drop problem. Any ideas what it could be, and am I right that I am narked that BG could of made my situation worse?

 

[dreadnoughtheating]

So can I assume that any of the guys you have had round have isolated the system from the appliance and left it long enough to see if the pressure drops abruptly when the system and boiler are 'reunited'?

just a thought. It would not pinpoint the location of any leak on the system.

When you say floorboards, do you mean 'laminate' flooring laid along, or worse, across floorboards/sheets?, is there concrete or similar below these floorboards?, or an open void?

There are specialist leak detection companies who insert a particular gas into the system and can apparently, for a fee locate the likely escape location. Does your BG cover include this sort of detection/remedial work?

DH

 

[Agile]

As far as I can see in this case BG have used reasonable diligence to try to isolate the fault when the underfloor area is difficult/impossible to access.

Of course thats providing they eliminated the unspecified boiler model as described above.

Tony

 

[rojaca]

why do you feel that bg have made the matter worse. You started of with no leak/loss of pressure. You then had a leak which has resulted in loss of pressure. BG have been out and, admittedly unsuccessfully, attempted to rectify it. I cannot see why you feel they have made the situation worse.

 

[daparojo]

The problem was solved.
BG hadn't tightened the fittings on the new expansion vessel and was leaking into a cupboard.

 

[Agile]

Usually the customer will notice something like that when they use the cupboard.

Particularly when they know there is a leak somewhere.

Tony

 

[daparojo]

Unfortunately Tony there is a washing machine in front of the vessell, and a gap of about 12 inches from the back of the machine to the back of of the cupboard. I felt the connections and they were dry, and by looking at the floor around the vessel it seemed dry. With a competent BG engineer you would of expected them to know how to tighten a few joints properly. It was only when the washing machine was moved (a big ask as it's built in), and the carpet underneat the machine was saturated.

 

[Agile]

Thats a result of cramming system components into an almost inaccessible place, often at the customer's insistance.

Compression joints leak if they are not tight enough and they also leak if they are overtightened.

I always check everything on the second or third day for weeps. The fit in a day are out just as soon as its filled with water.

Tony