BIASI PRISMA 24SE WALL HUNG COMBI BOILER - hot water problem

[vease]

The heating is working fine but the hot water is not continuous. Its does a cycle of hot - warm - cold - warm - hot etc etc. The boiler fires up to heat the water then turns off altogether instead of going to low flame.

Its been suggested that its either a faulty micoswitch or the heat exchange unit

Other people are just telling me to out it and get a new one but that costs so I was hoping to get it through to the summer at least

Any thoughts?

 

[lor]

dirt blocking the plate heat exchanger . Had the same fault many times

 

[Agile]

If you watch the temperature gauge it should not exceed about 60°C on DHW.

If it goes much higher then the plate HE is blocked. This is very common on a system which was not properly cleaned when the boiler was installed.

In the meantime it will work a little better if you turn the DHW temp dial down a lot and only turn the taps on less.

Tony Glazier

 

[vease]

It does go up to 80 or more!

a plumber did look at it but turned to up to maximum to give me some hot water?

Can the heat exchanger be cleaned?

 

[Agile]

Yes, it can be cleaned if you know how but many prefer to just change them!

Tony