Vaillant Turbomax F29 - What's the next step?

[danturbomax]

I have a Vaillant Turbomax with an F29 fault. When there is a demand for hot water the gas ignites initially, and the water is heated. However the gas then goes out and then comes back on (not sure if this is usual to control the water temp), it does this a few times but then the boiler fails to ignite and locks out showing an f29 fault.

So far the following has been carried out to try to resolve the fault;

Electrode cleaned
PCB Replaced
Gas Valve Replaced
and it has been cleaned thoroughly inside, jets checked for blockages, fan blades cleaned, heat exchanger fins cleaned.

The boiler is at 1.5 bar.

Any ideas on what to check next?

 

[ShaunCorbs]

Canoe filter ?

 

[Deleted member 120897]

Who replaced all of these components? Check simple things (as you’ve not listed them). Ecv is in fully upright position, inlet WP of the boiler, condensate arrangement, has the flue been checked?

 

[Deleted member 120897]

Canoe filter ?

Wouldn’t think so for ignition/lack of gas failure

 

[ShaunCorbs]

Wouldn’t think so for ignition/lack of gas failure

I’m guessing as the op hasn’t said anything it works on ch

 

[danturbomax]

Who replaced all of these components? Check simple things (as you’ve not listed them). Ecv is in fully upright position, inlet WP of the boiler, condensate arrangement, has the flue been checked?

All components replaced by gas engineer. ECV is fully upright, not sure what the inlet WP is? To my knowledge it's not a condensing boiler. I will ask them to check the flue. Thanks for the suggestions

 

[danturbomax]

I’m guessing as the op hasn’t said anything it works on ch

Not tried the CH, will check the canoe filter.

 

[Deleted member 120897]

All components replaced by gas engineer. ECV is fully upright, not sure what the inlet WP is? To my knowledge it's not a condensing boiler. I will ask them to check the flue. Thanks for the suggestions

Apologies, I don’t believe it is condensing (was thinking EcoTEC which is what I work on). WP is working pressure.