Biasi Combi Boiler will not light. Help!!!

[Dave Med]

Hi, first post on here so many thanks in advance for any replies. I have recently replaced several radiators and drained the CH system to do so each time. The last time however after refilling and bleeding the air from the system the boiler will not fire up. The pump seems to run and when turning on the hot tap I can hear a click but nothing else. If I hold in the safety thermostat reset button the boiler fires up as normal but as soon as I let go the button pops out again.
What have I done to my boiler??? Any help would be much appreciated.
The Model is a Biasi Prisma 24SE.

 

[Agile]

The overheat stat is a safety device to protect the boiler!

It seems you have been using it as a user control.

If you keep on resetting it more that 20 times is reduces its operating temperature and now it seems that you have completely broken it!

Its also likely that you plate HE is blocked ! If the temp guage goes over 65 degrees when using hot water then its blocked and that has probably been tripping the o/h stat as well.

This happens because the system water was not treated when the boiler was first installed.

Tony Glazier

 

[Dave Med]

Thanks for your reply, I have only pressed the reset button about 3 or 4 times and each time it pops out almost immediately to stop the burner so it seems to still be doing its job! What I need to know is why it is protecting the system from over heat when the system temp is cold (20 degrees on the guage). Is it possible that the safety thermostat is faulty and if so can it be replaced?

 

[micky p]

it may well be air locked in the boiler. i think they have a flow switch on the biasi so uless the air is completely purged then the system will not fire up. maybe the auto air vent is not working as it should in the boiler

 

[Agile]

Is it possible that the safety thermostat is faulty and if so can it be replaced?

I sometimes wonder why I bother to give good advice when no one reads it!

I have already told you:-

"""If you keep on resetting it more that 20 times is reduces its operating temperature and now it seems that you have completely broken it!"""

Did you have the boiler installed? That model was on sale between 1997 and 2002!

Could a previous owner have been pushing it every day?

Regardless it will need to be replaced!

The one thing you MUST not do is to jam it in as its a safety device to stop the boiler exploding!



Tony Glazier