Vaillant Boiler ignition issue

[LanceB]

Hi

I have a rather old vaillant boiler. Not sure of the model number but its like a VC GB 242 eh only not a combi, a 'normal' boiler.

When it tries to start the fan comes on and the ignition fires. Flames start but them immediatley go out and the ignition fires again. This all happens in a fraction of a second and continues for several attempts before it fires and stays lit. It then sometimes goes out after a minute or so.

The fan is sucking and water pressure is fine. Not sure what may be causing this. Perhaps the thermister/sensor to check the thing has ignited properly which is cutting the gas?

Please let me have your ideas

thanks

 

[kevplumb]

thermo compact

 

[LanceB]

it is a thermocompact.

 

[twgas]

most likely a problem for a RGI to sort.

 

[kevplumb]

most likely a problem for a RGI to sort.

quick scout through the mi's would suggest you are correct mick

 

[twgas]

thanks for the vote of confidence, I very seldom use MIs on here, can't be ar5ed to rifle through them,

 

[mickyg]

check the pumps running, if the pd switch dont make. no ignition

 

[kevplumb]

check the pumps running, if the pd switch dont make. no ignition

i was gonna say that

 

[Bunnyman]

U will need a rgi for this one it's a common fault with the old vcw range where reg maintenance ain't bin done properly,,the ignition rate creeps up so when boiler lights ignition is a bit fierce causing chamber to pulsate via air pressure switch switching on an off sometimes it will continue until lockout occurs

Untitled

• Bunnyman
• 26 Mar 2010
• 499

 

[Agile]

Are you are refering to the Vaillants where the burner pressure adjustment was under a lead sealed cover?

Years ago, I called Vaillant about one I found with the burner pressure very high and suggested the lead seals indicated they should not be touched.

The vaillant nupty told me they never gave any problem but if mine was too high then I could remove the seal and adjust it.

A few months later I received a recall notice to RGIs warning that all those models should be checked as burner pressures could become excessive!

Tony