Valliant pump issue

[BaronGreenback]

Have a strange one which i could do with some help with.

My Valliant 428 is failing to activate the pump.

I know the pump works fine as i've tested it with a 3a plug.

However, when wired into the boiler I get an F22 - boiler cable or pump fault - the boiler calls for the pump, however the pump never kicks in.

Have checked for a current through the pump wire from the boiler and there is something there (just discovered my multimeter is broke so i can't tell the exact voltage being presented).

The only thing i can think of is a) dodgy cable (which was working fine) or b) faulty motherboard.

Has anyone come across anything like this before?

Thanks

 

[Agile]

Have a strange one which i could do with some help with.

Have checked for a current through the pump wire from the boiler and there is something there (just discovered my multimeter is broke so i can't tell the exact voltage being presented).

Thanks

Well are you measuring current or voltage?

Do you know what each is?

 

[BaronGreenback]

not yet - will be picking up a new multimeter in the morning - i've been using a voltage screwdriver - so know there is something there.

 

[Agile]

Neon screwdrivers are pretty useless for anything apart from identifying what not to touch!

 

[DP]

OP, check the L, then the N at the pump with your neon driver. Does your driver indicate voltage on both?

Do same at the wiring centre. Post results

 

[BaronGreenback]

Multimeter shows zero volts both at the pump and on the PCB - so i don't know what the neon is picking up - but it's on both L and N.

Have tested fuse on PCB and it's ok - so it looks like the PCB is faulty ???

 

[Agile]

I am not confident of your testing technique.

What are you putting your meter probes onto?

Tony

 

[BaronGreenback]

Thanks for your response.

initially it was at the pump connection. Now - it's on the pump connector on the PCB.

Have to say that i am confused myself why the multimeter is reading zero, but the neon is lighting - I am assuming that this is down to it being an analogue tester, and that the neon picking up a v. small voltage. (Have tested the multimeter on a working item and it does measure a voltage.)

 

[BaronGreenback]

Have got my hands on a digital multimeter.

On the PCB, i can hear the click of the relay - however the voltage drops initially to around -4v and then randomly jumps to varying levels between -4v to +3v - so it looks like somethings blown.

Would i be correct in assuming a new PCB is in order?

 

[The831Bunny]

Are you testing to the incoming Neutral or the pump connection N terminal?

 

[ollski]

who's ever heard of a newish vaillant pump failing?, you'll be telling us they leak soon

 

[Razor900]

who's ever heard of a newish vaillant pump failing?, you'll be telling us they leak soon

It's not a Vaillant pump

 

[BaronGreenback]

N on the pump connection.

 

[The831Bunny]

N on the pump connection.

Set your meter to test in the 250VAC range. Firstly test from the incoming earth to the incoming Neutral. Make a note of the reading.

Then use your - probe on the incoming Neutral and the + probe to the N on the pump connector when the pump should be running. Then again between the incoming Neutral and the pump connector L.

Only test 230V live circuits if you are confident you are competent. Report back with your findings and we can go from there.

 

[ollski]

It's not a Vaillant pump

Whats the 428?, is that the glow-worm hxi?. Never been able to tell the difference between one vaillant and another as they call them all virtually the same thing.