is it the boiler or something else?

[Marina]

I have just moved, the house has a 10 month old Baxi Main 24 HE combi boiler and 9 radiators.

Over the past 10 days, problems started with boiler and radiators:
The boiler loses pressure - all the way down to zero, gradually - whether the heating is on or not. I have to top it up every time I need hot water, basically at least once a day. Yesterday I had to do it 4 times. Now it doesn’t even fill up properly. When the heating is on, it will lock out after a while, pressure right down and flame failure.
All of this has been getting slowly worse over the past 5 days or so.

I tried to bleed the radiators:
The downstairs ones (5) are ok, except for 1 that cannot be bled as it’s too stiff
The 4 upstairs ones: I can open valves, but nothing comes out, no air, no water. They do work though, ie they get hot when boiler works.

As the boiler is still under guarantee, I called a Heateam engineer, who said the boiler’s absolutely fine and the problem is elsewhere. He checked for leaks inside the boiler and the wall outside, no leaks.

Any ideas?

Many thanks

Marina

 

[Bernie2]

I don't know whether its been done or not, I imagine it has, but the usual thing is to check for any air in the system. Check PRV overflow. Check expansion vessel. And if no sign of a leak anywhere on the system. You then have to ask yourself where else the water could be going and without knowing the system its a bit hard to do that.

After all a sealed system is only like a balloon. It has to have a hole in it for the water to leak out, if its loosing pressure at a faster rate than is normal for the air in oxygenated water to be displaced when the water is heated causing a pressure drop.

 

[moony]

leak in system - if prv has been checked and expansion vessel hasnt lost its charge then check rad tails for leaks - pipework - any damp etc etc. if there is as much water lost as your saying (filling 4 times a day) then there is a pretty good leak somewhere.

 

[REDSAW]

check the prv again, there prone on theese boilers.
after 5 days i would have expected a noticable leak somewhere unless the pipes run under the downstairs floorboards.

 

[Toddyplumb]

If its only 10 months the installer should come back. There details will be on the benchmark !

 

[easyt]

If you are on a water meter then if there is a leak the little star shaped piece in the middle of the gauge will be moving. I thought I had an external leak last month and contacted the water company. They put a temporary meter on to test. (No leak - a natural spring). But it showed even a slow dripping tap. (I set a tap dripping very slowly whilst the guy was here as I wanted to see how sensitive the meter was).

If you are convinced there is no leak - but common sense says there must be you can always get a temporary meter fitted to confirm your worst fears. Are there pipes under floor boards?

 

[oldplumber]

If you are on a water meter then if there is a leak the little star shaped piece in the middle of the gauge will be moving. I thought I had an external leak last month and contacted the water company. They put a temporary meter on to test. (No leak - a natural spring). But it showed even a slow dripping tap. (I set a tap dripping very slowly whilst the guy was here as I wanted to see how sensitive the meter was).

If you are convinced there is no leak - but common sense says there must be you can always get a temporary meter fitted to confirm your worst fears. Are there pipes under floor boards?

You seem to have lost the thread here which will puzzle the initial poster as we are dealing with a sealed system thats losing pressure not a cw main thats leaking!

 

[GPSNewcastle]

Leak in the pipework somewhere, if its not losing pressure through the PRV then this has to be the problem....(there is not need for any meters/meter readings etc as this is a sealed system, you fill it up, it loses water through the leak then you fill it up again). It has to be somewhere under the floor if it is not noticeable as for the boiler to drop from 1.5bar to zero four times in a 24hr period the leak must be sizeable

 

[easyt]

You seem to have lost the thread here which will puzzle the initial poster as we are dealing with a sealed system thats losing pressure not a cw main thats leaking!

Yup. I was forgetting how they worked. dohh