LEAK UNDER FLOOR CAUSING GAS COMBI BOILER TO RUN ALL THE TIME??...AND WHAT IS THE PART?

[Dimmy]

Some advice needed please re a 3 year old Worcester Bosch combi gas boiler. The hot water works but no heating. A gas engineer was already booked to do the annual safety check before the fault developed. He said the boiler is ok with no fault. He said there must be a leak under the floor boards causing hot water to escape and that is why the boiler is contiually running as it thinks a hot tap is open. I have 2 questions please..
1. If there is an underfloor leak shouldn't the boiler pressure guage be dropping? but it is not..it is constant at 1.5 to 2 bar.
2. The engineer left this part behind after he did the safety check (see photo). Is it part of the boiler?..i have pictured it from both sides..many thanks!

 

[Madrab]

2. The engineer left this part behind after he did the safety check (see photo). Is it part of the boiler?..i have pictured it from both sides..many thanks!

Oh dear, look at the top of the boiler, where the flue comes out the top of it, You should see to 2 openings in it, one with a wee blank and the other that may be just an open threaded hole at the moment, if so that cap screws onto that open threaded hole, get it on there straight away.

something like this

He is talking about the HW that would come out of the taps, not the central heating. Leak in that pipe could keep the boiler running if the leak was bad enough

 

[oldbuffer]

1. A leak on the domestic hot water side will not affect the boiler pressure. It might cause the boiler to run continuously.
2. You could shut the main stopcock to the property. This should turn the boiler off.
3. If you have a water meter, wait until all toilet cisterns have refilled and completely shut all taps, hot and cold. If water is still flowing, shown by the meter moving, it can only be from the hot water.
4. Alternatively one of the valves under the boiler will be to shut off the hot water. You could try closing this valve and see if the boiler then turns off. The boiler manual will be available on-line to work out which valve it is. Be a bit careful, as these valves are sometimes poor quality and my fail to open properly or may leak.
5. If you are having an annual safety check, it sounds as if you are renting the property. If so, it is the landlord's responsibility to get the fault corrected.

 

[Dimmy]

Many thanks ..any idea what the bits are in the photo in my post?.. i think the gas engineer left them behind when he did the annual safety check..bit concerned if they belong in the boiler!..thanks