Ferroli modena 80E - Water too hot!

[dporteus]

Occasionally while running the hot water the temperature will dramatically increase causing me or the missus to bail out the shower in a dramatic comando style dive..

The increased temperature will last for a few minutes then go back to normal. The water pressiure doesn't drop but the boiler does make a growling sound (sorry not very helpful) All the lights seem to be normal & the burner is on.

Anythoughts??

Cheers

Dave

 

[chrishutt]

What type of shower? Does this occur at all hot outlets (if flow is turned down low), or just the shower?

 

[dporteus]

All outlets. It happened again this morning while the other half was in the shower, so I quickly turned on the hot tap in the kitchen to see what would happen, it was also too hot & thats when the growling sound started coming from the boiler which is in the kitchen. When I turned the kitchen tap off the growling sound dissapeared but the missus was still complaining it was too hot in the shower.

I was wondering if the thermostat sticks too low & so the boiler over compensates & continues to heat the water, although I'm not sure, hence the post..

 

[ChrisR]

First thing I'd do would be to check/change the temperature sensor. Its a varying resistance device. If it isn't varying enough/properly you'd get what you have.
Sludge or scale build up can give similar symptoms.

 

[dporteus]

thanks for your advice, i'll check it out..

Cheers, Dave