hot and cold

[norlandd]

Have Swiftflow combi located in student accommodation.Seven years old and has been fairly touble free until these past few months where a EV and PRV have been replaced.

There is still a problem with reducing pressure (has to be repressured up to 0.7 say twice weekly associated with the hot water being rather erratic. i.e hot water suddenly becoming cold and then extremely hot.

Not being resident at the property it is difficult to obtain accurate information on what exactly is happening but I wonder if anyone can suggest a link between the dropping pressure and the hot water behaviour.

Cheers
David

 

[ChrisR]

No Aha moment to tie the two occurs to me,

Pressure - do they bleed radiators, check the prv pipe again very carefully, leaks in the boiler, maybe from air vent (sorry dunno where it s offhand).
Have they adjusted rads - valve stems can weep and the hot water on them evaporates.

H-C-HW is usually sludge in the primary (system) side of the 2ndry heat exchanger. Delays in the boiler learning of how hot the water is, causes temp overshoot. It can be cleaned.

 

[norlandd]

Thanks for tips.

Time to call in Mr Corgiman again but at least I.ll know what he is talking about