ariston combi water too hot

[pepboycie]

My water from taps and shower is boiling hot and does not get cooler when I change temperature setting on boiler- any ideas??
thanks

 

[Agile]

My idea would be that there is a fault with the temperature control or settings within your boiler.

Tony

 

[pepboycie]

Thanks,
Guess thats a proffesional job, sounds expensive!

 

[Agile]

Whats expensive depends on your perception of whats expensive!

Tony

 

[pepboycie]

how do i contact you?
regards
mike

 

[BOB.DOLE]

My water from taps and shower is boiling hot and does not get cooler when I change temperature setting on boiler- any ideas??
thanks

could be mod valve not regulating, and the dhw thermistor could be faulty, burner pressure not correct,

 

[fela kuti]

i have been called out to an ariston micro genus with same problem.
the hot water comes out about 80C at which point the burner shuts down,when water cools down burner will relight. The dhw thermostat will not control the water output temp.
I swapped the thermistors around and the fault remained.
I then removed pump and secondary heat exchanger and cleaned them not very dirty.
checked pump spindle spinning at speed ok.

This is the point at which i gave up.

 

[ChrisR]

Did you check modulation and both burner pressures, and the flow rate through the boiler?

 

[micky p]

microgenus combis are renound(spellin) for sludgeing up. If it has been installed on an old system them this may well be the case. When i have gone out to them in the past i have had to completely strip the boiler boiler and even wash the dhw plate heat exchange out with acid to remove the sludge. I think in your case it sounds like you thermistors are playing up. try swapping both of these and see how you go on.

 

[fela kuti]

Have fixed the boiler now.
The problem was that the burner was not modulating and leading to the water being heated to rapidly with no chance for the thermistor to react and control dhw.
On return i rechecked burner pressures high and low,there was no flame on the low setting with the leads to the modreg disconnected,the boiler went straight to lockout.
Adjusting the low pressure screw i managed to get a flame and set min burner pressure.the boiler now works properly again.
Somehow the min pressure altered?

Thanks nick

 

[micky p]

Have fixed the boiler now.
The problem was that the burner was not modulating and leading to the water being heated to rapidly with no chance for the thermistor to react and control dhw.
On return i rechecked burner pressures high and low,there was no flame on the low setting with the leads to the modreg disconnected,the boiler went straight to lockout.
Adjusting the low pressure screw i managed to get a flame and set min burner pressure.the boiler now works properly again.
Somehow the min pressure altered?

Thanks nick

i have had this happen to me before on a styx (ariston) combi. strange how the pressure alters wothout no one touching it it