vokera fan

[cliffybabes]

Hi
I have a Vokera excell 80SP and the idle speed on the fan is not working (it kicks in full speed when heating/hot water is on) I have a spare boiler and have changed the fan, although I did check with volt meter first and it was not live but I changed the fan over anyway. I then changed over the PCB and still no live feed to fan; I have also changed a gold coloured condenser, but still no joy.
I have lost my trouble shooting guide and now at a loss as what to do?
Can anyone help?
Regards Cliff

 

[scatmanjohn]

so you have changed the fan, pcb, slow fan speed resistor (560ohms i believe)

Ooops.

check the boiler flow switch...is the pin going in and out as the pump starts/stops.
if it is check the condition of the microswitch

 

[Agile]

The gold "coloured thing" is a resistor !

Can you measure the resistance? Should be about 560 ohms!

I think we decided the fan speedup is provided by the PCB but my colleagues will confirm that.

Professionally we dont use used boiler parts to check anything unless we have fully tested them first as it can waste a lot of time.

Tony

 

[geoff@cetltd]

either the fan speed relay on the pcb has gone, the 560 ohm resistor is open circuit or the bearings on the fan are on the way out and the low fan speed voltage isn't enough to get it to turn.

I can't remember exactly what you said in your original post

 

[cliffybabes]

I have checked the resistor with the multi meter and the reading was 000, I take it this means its b*****ks????

 

[pannierstan]

I would seriously suggest you check the pump flow switch pin is moving.

A simple grease will usually sort the problem or better still a new diaphram and spindle gland again with a touch of silicon grease on the spindle

Stan

 

[cliffybabes]

hi pannierstan

The pump flow switch is ok (just checked it again) it moves out when flow and hits micro switch to turn full speed fan on.
The problem with mine is there is no low voltage feed to the fan when just the pilot light is on and water/heating off?

 

[Agile]

Cliffy, if the resistor is open circuit then THATS THE FAULT !

I dont know why others are suggesting anything different!

Change it for one that reads 560 ohms!

Tony

 

[cliffybabes]

Hi Tony

Gonna try and get one tomorrow, will let you know outcome.

Regards Cliffy

 

[geoff@cetltd]

I have checked the resistor with the multi meter and the reading was 000, I take it this means its b*****ks????

It's so unlikely that the resistor has gone short circuit that I think you should get someone with a clue to take a look

 

[DP]

Raden, I think you mean open circuit.

 

[cliffybabes]

raden

The first time the combi went t*ts up I got someone with a clue to come and have a look! (out off yellow pages, corgi registered) He told me the PCB had gone and the cost with labour would be £350, but he said that he could install me a new combi for £450 and as the vokera was 5 years old and could go wrong again (his words) I would be better to just get a new one.
I told him I would get back to him. I got the trouble shooting guide out and traced it to a faulty micro switch. (it cost me £4.99 + vat from plumb center)
Ever since I have repaired and serviced it myself (another micro switch and the fan renewed over the last four years).
Regards Cliff

 

[ChrisR]

Trouble is, being Corgi regd only gives an odd clue here or there about boilers. When I did it the "training" on boilers - mostly gas matters, was half a day.

Suggest you double check that you got a good contact on the resistor and that the meter was on an appropriate range, like 2000 Ohms max.
Sorry if that's egg sucking lessons.

You could always measure the voltage across the fan and resistor when it's supposed to be going slow...

 

[Rob]

Measured slow fan voltage on a puma today, got 90vac. obviously different boiler just an indication.
Did i read though in your first post you've changed the slow fan resistor?

 

[geoff@cetltd]

Raden, I think you mean open circuit.

no, I meant short circuit

it's a coil of wire on a ceramic former surriounded by a ceramic cement - highly unlikely to have gone short circuit, as I said