Loss of pressure on Vaillant EcoTec pro 28

[Ellog]

Hi to all members.
I'm a new member to the forum and have spent time prior to joining in researching this and other forums on this matter. There are no leaks from rads or rad valves. Reluctant to lift fitted carpets at this stage and there are no obvious water stains showing on g.f. ceilings.
No leaks from boiler casing. PRV is not leaking outside. Is it possible that the diverter valve is not fully working or obstructed and is now allowing heating water to seep into DHW. Pressure appears to drop more so when running a bath? Any thoughts would be appreciated.

 

[landyandy]

If your pressure is dropping either you have a leak somewhere or the pressure relief valve is passing. Start with the radiator valves feeling at the back and tie a plastic bag over the prv to see if it's passing.

Andy

 

[Ellog]

I will investigate as per your advice over the weekend and report findings . Thanks.

 

[Ellog]

OK Andy, perhaps the most obvious and least expensive option at this stage and the correct way to go. The plastic bag did confirm no leaks on the PRV and the check on the rads produced no surprises. Because there was no glaring stains on the ground floor ceilings (boiler is situated upstairs), I bit the bullet and lifted the fitted carpet in the room with the boiler. The reason being it is over the kitchen which has plastic cladding on the ceiling and straight away discovered a straight push fit connector joining the plastic return to the copper boiler tail was weeping, possibly due to having had some electrical cabling recently routed in the floor space (blame the spark!). Spot on pal.