vent pipe shooting steam into header tank in loft

[jimadams]

we have a worcester bosch greenstar 24ri condensing boiler when the boiler fires up its ok but when it switches off during its cycle it vents steam and causes huge vibration in header tank in loft,could this be a faulty thermostat on boiler,i should add that i have turned the temperature control down to half and this has cured the problem but the boiler now runs all day and doesnt switch on and off automatically

 

[macackau]

Get a gas safe registered engineer in to take a look ASAP.

 

[Dotty]

Absolutely. You've something very wrong with the way it's been plumbed in.

 

[Stu Davis]

Bet they havent wired the pump back to the boiler re over run, comon installer problem. When boiler cuts off on high no pump over run and they dont like it !!!