Ideal Logic Combi 30 boiler

[Sneakysam63]

I’m regularly getting an F1 fault code. Low system pressure. A check on the radiators show that they don’t need bleeding. I have been through the entire system and can find no trace of any leaks, however the boiler will reset once I’ve charged the system via the fill valve, it’s only a short burst to do this.
The condensate trap is also completely full and has needed draining frequently. I suspect the condensate trap is a separate issue possibly a blocked drain.
Two questions. Is there any connection between the two issues.
Is there anywhere I can attach a pressure gauge to see if my water pressure is reducing thus indicating a leak somewhere I haven’t found.
Or is it possibly a pressure transducer needing replacing?

 

[jj4091]

Isolate the flow and return valves at the boiler and if it still loses pressure overnight it is a boiler fault. You could have an odd shapped copper pipe that comes through wall then falls vertically then points to the wall again this is connected to the pressure relief valve and releases excess water if the pressure gets too high. Fix a small clear plastic bag to this and see if any water is collected in it. The condensate trap should partially fill up to the top of the divider then spill over into the drain pipe. If iit is going higher than the divider then you do have an obsruction but I think that will be a different issue. Various possibilities as to where the water is going if it is the boiler but you need to establish that first.

 

[thomp1983]

You shouldn't really have the front cover off the boiler.

If you've not used the taps thtlat isolate the boiler in awhile the it's likely they won't work and will still allow water to pass.

Your issue is likely to be either the expansion vessel or heat exchange vessel, both common issues on the logic+ boilers, neither particularly cheap to fix once you get a gassafe plumber in to do the work.

 

[kidgreen61]

Your expansion needs recharging by the sound of it.

 

[robbro16]

The pressure gauge on the boiler registers the system pressure so putting another pressure gauge elsewhere on the system pipework will record the same pressure. If the expansion tank diaphragm is holed then the pressure will rise to an abnormal higher pressure (check there are no drips coming from the safety relief valve outlet) when the boiler is firing due to the specific volume of water rising with temperature. To check the expansion tank depress the schrader charging valve and if water comes out then the diaphragm is holed. However this will not cause a drop in system pressure. But the expansion tank cannot be recharged.

If there are no drips coming from the bottom of the boiler or the safety relief valve then the leak is in the flow/return piping or radiators. This is going to be more difficult to find especially when the pipework is not exposed. Check every part of the exposed pipework and radiators for drips or damp patches. If you cannot find the leak then there are central heating leak sealers which are supposed to stop small leaks which I have never tried. A more obtuse method would be to disconnect the flow/return pipework from the boiler, drain down, and pressurise with air to say 2 bar to start with and listen for a leak,

 

[robbro16]

You also need to check that the main heat exchanger (heat engine) is not leaking. Any such leak would end up in the condensate piping system. You will need to expose the condensate pipework downstream from the condensate trap. Depressurise the boiler completely and isolate it from the flow/return pipework. Turn off the cold water supply to the boiler. Wait until the the condensate pipe stops dripping then slowly repressurise the boiler via the filling loop to say 2 bar and wait to see if drips start coming from the condensate pipe. Other than an exterior leak the plate to plate heat exchanger should increase the system pressure as the cold mains pressure is generally higher than the system pressure (1.0 - 1.5 Bar).

 

[kidgreen61]

But the expansion tank cannot be recharged.

Why not?
Part of an annual service in my book.

 

[jj4091]

Why not?
Part of an annual service in my book.

Not if there is a hole in the diaphragm