Central Heating pump not working

[MrGrowser]

The circulation pump on my quite old central heating unit has stopped working.
This pump is a WILO GOLD 50 which was fitted about three years ago to the unit which has been in place for over thirty years.
As it will rotate OK when using the slot in the end of the shaft, I thought the problem might be the capacitor which is 2.6. microFarad value.
However none of the firms in Lincoln will supply a spare capacitor (which if it worked would be a ten minute job), preferring rather to sell me a new pump which would be a much more awkward job to fit and might not even cure the problem.
Can someone advise me please?

Plan B is to call in a plumber. Plan C is a new boiler but would be expensive.

 

[cross thread]

buy same pump and swap the head

 

[matt1e]

or just change the capacitor
try maplins or RS components (the later tends to deal trade only) or similar

failing that,give wilo a ring

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Matt

 

[muggles]

Or fit a Grundfos Alpha+, which is a better pump and although initially more expensive, will pay for itself in saved electricity bills due to it's much lower power consumption

 

[Taylortwocities]

IIRC the capacitor is just to eliminate interference so if its bust you'd get noise on your telly.

Have you absolutely confirmed that you are getting mains voltage across the live and neutral connections to the pump?
You'll need a test meter - not a neon screwdriver - to check that.

 

[MrGrowser]

IIRC the capacitor is just to eliminate interference so if its bust you'd get noise on your telly.

Have you absolutely confirmed that you are getting mains voltage across the live and neutral connections to the pump?
You'll need a test meter - not a neon screwdriver - to check that.

Thanks for the advice - I was thinking the capacitor was to assist starting? Still can't obtain one but was going to try Maplin's again.
I shall try the voltage with a meter but was led down the path of capacitor.
What is wrong if there's no voltage?
The pump manufacturers will not supply a capacitor but will sell me a pump.
Good job I'm not desperate - using electric fires

Looks like I'll need the professionals in? Thanks anyway to all!

 

[MrGrowser]

IIRC the capacitor is just to eliminate interference so if its bust you'd get noise on your telly.

Have you absolutely confirmed that you are getting mains voltage across the live and neutral connections to the pump?
You'll need a test meter - not a neon screwdriver - to check that.

I like the bit about tying a knot in the rope!

 

[Taylortwocities]

What is wrong if there's no voltage?

It will be whatever switches the pump on! it could be from the boiler, or it could be the central heating controller, or one of the valves not working properly.

Do check if there is voltage across the input terminals. If you havent got a test meter then connect a light bulb across the terminals (safely!). The bulb will come on if there is power there.

 

[matt1e]

IIRC the capacitor is just to eliminate interference so if its bust you'd get noise on your telly.

Have you absolutely confirmed that you are getting mains voltage across the live and neutral connections to the pump?
You'll need a test meter - not a neon screwdriver - to check that.

no its not

Thanks for the advice - I was thinking the capacitor was to assist starting? Still can't obtain one but was going to try Maplin's again.
I shall try the voltage with a meter but was led down the path of capacitor.

you're right it is

matt

 

[Scobi]

The capacitor is not there to suppress interference, it's specifically to start and run the motor.
Open the large slotted screw on the rear of the pump ( not the impellor end) and inside you will see the end of the motor shaft and a slot in the centre.
If you spin this rather quickly you may find that the motor will run, provided that there is power getting to it, and it will continue to run until you switch off.

If this is the case then replacing the 2.5 MF capacitor will cure the problem. You should be able to source the capacitor in with Maplins or CPC Farnell (RS)