Over heating combi boiler

[pinb]

I got a 15 year old Saunier Duval Thelia 623 boiler which has developed a fault over the last 2/3 months. When the central heating is off and the hot water is run for sometime, ie shower/bath, and then turned off, the burners go off but then after another 30-60 seconds, the water pressure increases until the boiler shuts down. I've had someone out to look at it and he de-scaled it and said that it could be a number of things

 

[Andy165]

Combis are designed to last about 10 to 15 years . Time to think about getting a new one. You are probabley going to start throwing good money after bad if you carry on trying to repair your existing one. Is it a combi?

 

[Agile]

I got a 15 year old Saunier Duval Thelia 623 boiler which has developed a fault over the last 2/3 months. When the central heating is off and the hot water is run for sometime, ie shower/bath, and then turned off, the burners go off but then after another 30-60 seconds, the water pressure increases until the boiler shuts down. I've had someone out to look at it and he de-scaled it and said that it could be a number of things

He evidently had little idea of how to diagnose faults in boilers!

I hope you did not pay him anything as he could not find the fault and his "descaling" was not required!

Tony

 

[bengasman]

and then turned off, the burners go off but then after another 30-60 seconds, the water pressure increases until the boiler shuts down.

Not quite sure what you mean by this, but sd of that age might well be worth replacing if it is anythng major. corrosion and mechanically weak parts that are very expensive make this one awkward