vaillant, failed today!

[REDSAW]

turbomax plus 834, fires up for a min or so then goes off then cycles again. pressures 1.5bar.
f22 on index fault.
there is no heat transfer on any pipes below or inside boiler from p-hex apart from h-ex f&r pipe! pump and fan running!!!!!!!
help
gone home:disappointed:

 

[GrahamM]

Pump or divertor Knackered or blockage. Sometimes faulty thermistors give F22.

 

[REDSAW]

Pump or divertor Knackered or blockage. Sometimes faulty thermistors give F22.

it says dry fire!
there was a small weep above the therm on the high stat that was dripping on it but i sorted that and dried it!
my initial thought was the motor pin on the div-valve but thought it will be open to heat or hw though?
cant understand why its not pushing anywhere down pipes unless its blocked solid!

ta

 

[Roger Welton]

was it going around the plate?

 

[Billy Bob Bob]

What resistance are you getting on the primary(CH) Thermistor

 

[REDSAW]

was it going around the plate?

yes, getting hot but not out!

 

[REDSAW]

What resistance are you getting on the primary(CH) Thermistor

15ohms

 

[Billy Bob Bob]

15ohms

Back to what Graham said ,is the pump working?

 

[mfgs]

Pump or divertor Knackered or blockage. Sometimes faulty thermistors give F22.

Agree with this. Sounds like you've ruled out the thermistor if 15k ohms at room temp? Look at the pump and diverter.

 

[Last Plumber]

Sounds like a blockage to me, check filter/strainer and pipework internally from primary heat ex as well as what above have said

 

[REDSAW]

Back to what Graham said ,is the pump working?

yeh, pumps running on my grundfoss magnet
i was thinking the plastic motor on the diverter as i didnt see that move inside. then somethings telling me blockage too or both!
problem was only allowed an hour to sort then it goes for authorization on repair costs so cant go beyond that time. this one beat me today...and the cost of parts for these is no hit and miss affair!

 

[tamz]

If it has the rubber hoses on it they will prob be choked up

 

[spike.gb]

Has the bypass failed and heat flowing straight into the return causing the boiler to heat up too quickly?

 

[Dogby]

One thing can check for is if the pump has separated from the impeller, had that once so it looked like pump was working but not pumping anywhere.