Potterton Puma 100e -start of winter- HW fine CH not working

[adj]

I put the central heating on the other day. I haven't used it since last spring.
The HW for the shower etc has worked fine all summer.

When I turned the heating on the boiler heats but then turns itself off without the radiators warming.

I supspect the pump may have seized up over the summer. Is there a way to turn it manually a couple of times in case it's just a sticky mechanism? Are there any other possibilities?

Thanks

There's are picture of the boiler here

http://www.7seals.co.uk/assets/images/puma 100e/CRW_5832-01g.jpg

 

[Gasguru]

I see the boiler has had the usual PCB replacement as well as a pump.

That pump was replaced under a British Gas service contract - is the boiler still covered?

If the pump had a problem you would normally find a problem with the hot water as well.

The common reason for the heating not to work would be due to a dripping hot tap. The slightest drip can stop the heating functioning.

Failling that and aussuming the radiator valves are open the boiler diverter valve often stick - they normally last 6 or 7 years before failing.

It is normal for the boiler to fire up initially in heating mode. The pump will continue to run allowing the diverter front setion to heat up - this causing the rear section to open up flow to the rads whereupon the burner will fire up again.

 

[Agile]

What a beautiful picture!

The Puma will continue to give hot water even if the pump is stalled on your model.

Unscrew the black nut on the pump anticlockwise and pull it forward and turn it back and forth and see if it turns freely. A little water may come out so have a rag ready.

If it still does not work then the diverter may have failed.

Tony

 

[adj]

Thanks Gasguru and Tony

I checked the taps are tight and unscrewed the motor. It appears to be turning freely.

Maybe it's the boiler diverter valve then.

Would that be a fairly straight-forward job to replace myself or is it time to call a pro? The boiler was there when I moved into the house. I don't know anything about a contract. The pump warranty says 30-04-04 (see the pic).

Maybe someone could point out the valve.

If you want to see the other pictures I took they're at:

http://www.7seals.co.uk/assets/images/puma 100e/CRW_5830-01g.jpg

http://www.7seals.co.uk/assets/images/puma 100e/CRW_5833-01g.jpg

http://www.7seals.co.uk/assets/images/puma 100e/

Many thanks

Andy

 

[Gasguru]

To be certain there is no hot water flow it is best to isolate the cold water feed to the boiler and then check if the heating still does not work.


The diverter valve is the brass lump to the left of the pressure gauge (it has two pipes on the front of it).

I'd advise getting in a pro as its not the easiest of jobs and clearance may be a problem when removing the rear retaining nut (your filling loop non-return valve may be in the way).

It is normal to find a few other problems when replacing the valve - eg pressure switch no longer works, air vent leaks etc so I normally replace these parts as routine. Make sure the expansion vessel is also checked for pressure.

 

[breezer]

doesnt this boiler have a wax capsule diverter?

I only ask because its the same boiler i have (except for the integral time switch)

 

[Agile]

If they have the same name then I expect they have the same parts inside!

To the OP, when you take hot water does the pump seem to be running?

You can check by trying to engage the black knob and you will then know if its running!!!

It is meant to run when taking DHW.

Tony

 

[pannierstan]

You might get away with just changing the wax capsule on the end of the divertor, but I must admit you would need to know the condition of the system water to start making a descision like that.

Stan

 

[adj]

If they have the same name then I expect they have the same parts inside!

To the OP, when you take hot water does the pump seem to be running?

You can check by trying to engage the black knob and you will then know if its running!!!

It is meant to run when taking DHW.

Tony

Hi Tony

I looked again. The black knob I unscrewed a bit

http://www.7seals.co.uk/assets/images/puma 100e/IMG_1122g.jpg

http://www.7seals.co.uk/assets/images/puma 100e/IMG_1127g.jpg

The axle inside turns only when it's unscrewed like this

http://www.7seals.co.uk/assets/images/puma 100e/IMG_1128g3.jpg

When I screw the black knob back in it makes a noise but the black knob doesn't rotate.

To identify the wax capsule on the end of the divertor I took another photo.

Can anyone see it?


http://www.7seals.co.uk/assets/images/puma 100e/IMG_1131g.jpg

I also tried the running the hot water. There was no difference between HW and CH. It made a noise but the black knob didn't move and neither did the axle.

Thanks again

 

[ChrisR]

Yer pump's turning OK then.
See partsarena.com/baxi :

 

[adj]

Thanks very much for your help guys.

I got round to replacing the diverter today. It was a bit fiddly at the back as Gasguru had warned. The old diverter does seem sticky now I have it off.

Gasguru said:

It is normal to find a few other problems when replacing the valve - eg pressure switch no longer works, air vent leaks etc so I normally replace these parts as routine. Make sure the expansion vessel is also checked for pressure.

When I finished the hot water works fine still. The radiators are still not heating though. When I move the CH switch from off to constant, the boiler fires up for a few seconds and then turns off.

I think the diverter was the major problem.
Should I look at the pressure switch, air vent or expansion vessel first? Is there anywhere I can get instructions on what to check for?

Thanks

ADJ

 

[adj]

I'm still getting no joy with this thing. I take it that you mean the water pressure swtich (with the yellow arrow) and not the air pressure switch.

http://www.7seals.co.uk/assets/images/puma 100e/CRW_1352-01g2red.jpg

ADJ

 

[Agile]

Where did you get the replacement diverter from?

Have you followed the early advice of turning of the cold feed to the boiler?

Have you waited at least 6-7 minutes before thinking its not giving CH?

Have you turned all the rads on?

Have you checked the CH pipes are clear right up to the boiler?

Tony

 

[ChrisR]

If the HW works, none of pressure switch, air vent etc could be a problem.

The front end of the DV needs to be warm for the CH to work - you can help it.. It should get warm when the boiler runs and there's no tap HW flowing. Does the pipe out of the back of the DV get hot (ch flow). Could be your pump's sludged up or going slow.

 

[adj]

Thanks Agile

Where did you get the replacement diverter from?

I got it on ebay. The plumb centre were quoting about £120 which seemed a bit steep.

Have you followed the early advice of turning of the cold feed to the boiler?

Yes, I did that. I did it again today (with the new diverter in) and still no heating.

Have you waited at least 6-7 minutes before thinking its not giving CH?

Yes, I waited a good half hour.

Have you turned all the rads on?

Yes, all the radiators are are on full.

Have you checked the CH pipes are clear right up to the boiler?

I'm not sure what this means. How would I go about doing that?