Vokera Compact 25HE

[JAP&H]

Hi all.

Pulling hair out (not much left)

Compact 25HE - Ignition sequence ok when demand for DHW, burner lights and water is hot at the outlet.

However, the temperature continues to rise until the primary thermistor puts the fire out. Pump continues to run and the appliance re-lights once cooled (the time of this varies).

Same thing happens during heating demand.

I have unplugged primary thermistor and plugged in a new one leaving it external to the heat exchanger. The boiler runs continuously under this test, kept an eye on temperature and shut tap before tripping high limit stat.

Plate to plate, heat exchanger, thermistors, pump, diverter valve and motor all checked - clear. Venturi's cleaned, flue not blocked. Fan ok.

Am I missing something simple? Advised landlord he may have to call vokera.

Any pointers appreciated in advance.

 

[diamondgas]

Check the modulation coil ... If you're GSR you'll know how to test hi and low modulating pressures too yeh?

 

[JAP&H]

Thanks Diamondgas.

Solenoid getting correct voltage from board and showing correct resistance listed in MIs.

High and low pressures check out, got it into my head that it's a restriction in flow issue but can't find the blockage.

Tennant good as gold (she only notices when showering). Landlord bleating on about costs but wants it sorted, he's thinking of putting property on market.

Thanks for your advice, will mull over problem in beer garden of local when I take the dog for a pint.

 

[Barry98]

everything becomes clear in a beer garden

 

[JAP&H]

Must dash whilst the hot orange thing in the sky is still working.

 

[diamondgas]

Thanks Diamondgas.

Solenoid getting correct voltage from board and showing correct resistance listed in MIs.

High and low pressures check out, got it into my head that it's a restriction in flow issue but can't find the blockage.

Tennant good as gold (she only notices when showering). Landlord bleating on about costs but wants it sorted, he's thinking of putting property on market.

Thanks for your advice, will mull over problem in beer garden of local when I take the dog for a pint.

If it's reaching temp of high limit on minimum pressure then there'll deffo be a restriction in the primary flow ... Weird that the water is getting hot though unless the hot water flows really poor?

Enjoy your beer

 

[richard frith]

is the boiler not in warranty dead easy vokera come out change wiring loom.as most problems have been this

 

[richard frith]

sorry to say fitted myself probably 60 of there boilers now when i turn on if there is a problem they come out then fix it. never been back to any others since 5 years long may it last fitted some Worcester and had more problems the last one was only we can fix them so i now fit vokera compact as the others are getting too much tecnology

 

[JAP&H]

Hi all thanks for your posts.

Got in touch with local Vokera bloke, Glen (my new bestest mate).

He suggested draining down and checking for blockage behind drain point as this is where the auto bypass is and it may be stuck.

Cleared out the gunk, re-assemble and fill.

Boiler now operating correctly and safely in both modes.

Plonking forward to the next one!

 

[diamondgas]

Crackin tip I hope i remember JAP&H