Hot water getting too hot on a Ferroli Optima 700

[choco]

A chippy mate of mine has just called me to say that the hot water coming out of his Ferroli Optima 700 combi is getting way too hot.

The flow rate seems normal and he has even increased the mains pressure to see if that would help, but it hasn't.

I haven't looked at it yet, so am looking for a few pointers on what could be causing it? I'm not brilliant on combis but I am Gas Safe registered, so I'll be trying to sort him out over the weekend.

 

[stevetheplumber]

if the flow rate is right it must be a thermostat or thermistor for hot water temp failed

 

[diamondgas]

A chippy mate of mine has just called me to say that the hot water coming out of his Ferroli Optima 700 combi is getting way too hot.

The flow rate seems normal and he has even increased the mains pressure to see if that would help, but it hasn't.

I haven't looked at it yet, so am looking for a few pointers on what could be causing it? I'm not brilliant on combis but I am Gas Safe registered, so I'll be trying to sort him out over the weekend.

Thermometer and flow cup is what I'd suggest you take choco. The cold mains supply is getting a lot warmer just now which may have raised his hot by as much as 10 degC. That can be the difference from bearable to OUCHYA...!!!

 

[Koogatubac]

Im having a similar problem with a baxi 105 mate, i think its the DHW Sensor (thermister) so im about to change that. Will let you know how i get on if she'll even turn up!! Lol water was getting scalding and boiler overheating then wouldnt light till it cooled down