Baxi duotec system loosing pressure

[MikeyWB]

Hi all this is my first post so here goes.

Recently had new Baxi duotec 28HE combi and all new rads (9) to replace 30yr old gloworm gas guzzler. House now heats up much quicker but seem to have a slow leak on system somewhere?

System has been topped up / repressurised about 4 times by me and on one occasion did not relight. Had Heatteam engineer out who replaced the pressure switch as he felt it could have been sensitive.

System was repressurised with the needle indicating on the gauge at the top of the 1 bar operating zone.

The needle position on the guage remained steady but seems to shift over a period of approx 2 weeks gradually to the bottom of the 1 bar operating zone. It is at this point I have been topping up.

My installer / heatteam have found no obvious leaks around boiler.

I have been under the floorboards and checked new joints for soundness and there is no evidence of any staining in ceilings (lath & plaster)

I have checked all new rad valves both cold and hot and no visible leaks.

The master bedroom rad keeps getting air in and has been bled probably twice since installation in October and subsequent topping up.

I'd appreciate any ideas / feedback before looking further for leaks under the boards again.

Thanks for your help.

MikeyWB

 

[ChrisR]

Check the pressure relief pipe (outside).
Recheck rad valve stems.
You can fill to 2 bar if it helps find the leak.
You might try Leak Sealer, but ask Worcs first.

 

[MikeyWB]

Thanks ChrisR.

Vent pipe outside is dry and no evidence of discharge.

Rad stems seem fine.

Think I may have found problem though. Magnaclean lid is leaking and is tracking down the casing but not always noticable because of evaporation.

Have collected approx half pint in 24 hours so hopefully this is the route cause.

My installer will visit next week to fix hopefully.

Many thanks

MikeyWB

 

[Agile]

You could check the lid is tight.

They say that it only needs to be single hand tight using the spanner but my experience is that many need to be quite tight. One I had to take off and out to the street to undo ( using a hammer on the spanner! ).

Some have cracked the lid/casing too!

Tony