Boiler only runs for a minute

[Matthew D]

I have a Vokera easy heat 25Ci LPG that alarms out after a minute or so, engineer has investigated and decided the flame sensor was at fault so fitted a new one but the fault remains. In the minute or so the boiler is on it repeatedly fires up then stops before eventually faulting out after about 5 attempts. Fan and pump are fine - rads or water get warm while the boiler is trying. The engineer now says it needs a new PCB but that's a lot more than the sensor and I'm not confident he's right.

Any thought on other things to try before I fork out for a new PCB?

 

[ianmcd]

bet it is reversed polarity, yes you will say no way but it will be

 

[Matthew D]

I'll mention that but he did run a series of electrical checks - is it the sort of thing where you can just try reversing the polarity and trying or will that fry the pcb or for that mater if that is the problem is the PCB already fried?

 

[vulcancontinental]

I hope the OP reports back. The easiheat Ci has a 5 year warranty so you shouldn't have to fork out for anything. Was it a Vokera engineer?

When you say it runs, I'm assuming you're getting no heat but simply listening to the fan or pump sound.

There were a batch or faulty flame sensors some months ago so that's where I'd look as well. Reverse polarity would show the same as Ian says.

Does the display show 01? ignition. If it shows anything else when the boiler stops let us know.

All assuming there's gas in the bottles and to the appliance.

 

[ianmcd]

No wont fry the PCB it just wont rectify with reversed polarity, forget about the colour of the wires, L to N 230v AC , L to Earth 230V AC, if you get N to Earth 230V AC that is the problem you have reversed polarity, yes girls I also know all the rest , but N to Earth confirms it, before you all get on your osillyscopes and flux capacitators , if you have lost a neutral it will never rectify the test I advised will confirm LN&E and whether the polarity is correct, I am a Vokera agent and I see reversed polarity a lot

 

[Matthew D]

There has been some electrical work done so reverse polarity is defiantly a possible. While it briefly runs it does give heat to rads or water, he's checked the gas pressure and that the boiler is setup for LPG. He's "not a fan" of Vokera which is whilst I was a bit dubious about the PCB - that and the cost. Yes error code is 01 and a solid red light.

 

[Matthew D]

Well it turns out Ian was very nearly right; I bought one of those socket checking plugs and tried it in the boilers socket, sure enough it went beep beep but not for reversed polarity but for an earth error, to cut a long story short the earth wasn't bonded to the neutral so was floating between the two. Quick fix at the DB and all seems fine. Not sure why the 4 letter acronym I can't remember earth protection thing did not trip?

 

[JohnD]

the earth wasn't bonded to the neutral so was floating between the two. Quick fix at the DB

oh dear

what did you do?

got any pics?

 

[Matthew D]

Just a 4mm wire between the neutral and earth bus bars plus a belt and braces wire from the earth bus to the ground spike. I'll get some more wire and put in common earth's on all the major items this evening. Sorry no picture.

 

[ianmcd]

Well it turns out Ian was very nearly right; I bought one of those socket checking plugs and tried it in the boilers socket, sure enough it went beep beep but not for reversed polarity but for an earth error, to cut a long story short the earth wasn't bonded to the neutral so was floating between the two. Quick fix at the DB and all seems fine. Not sure why the 4 letter acronym I can't remember earth protection thing did not trip?

No I was correctly right and I dont care if your so called engineer is a fan of Vokera or not, If I can tell you what the fault is from a laptop and your so called engineer in front of the boiler cant, then you need a new Engineer, noting wrong with Vokera boilers

 

[Matthew D]

Ian, I couldn't agree more, unfortunately finding a competent engineer isn't always easy. Just out of curiosity why does the flame sensor need a good earth?

 

[Agile]

The flame sensor creates a small current through the flame to the earthed chassis of the boiler.

So the potential difference between neutral and earth must be small.

If you do not have an earth connection with the supply then an earth spike might not be ideal.

 

[ianmcd]

just the way your boiler works, German boilers Worcester etc can be plugged in either way round, Italian boilers are polarity sensitive, doesnt mean they are bad boilers, they just do what the were designed to do @vulcancontinental works for Vokera , maybe he can go into more detail, but I for one would have sussed this in minutes , your engineers diagnosis is unfair to the brand