Potterton Puma 80 - No Hot water or Heating. Pilot Ok.

[jenicks]

It's been a while for this update, until recently the heating has been fine and the H/W still hit and miss. Now we have neither again. 3 videos below that may or may not help.

A new DHW Flow Switch + Microswitch was fitted last year and seems to be operating fine. HW Demand LED lights okay on demand.

The pilot is fine and stays on now. Last year I bent the thermocouple a little towards the flame as the fan was constantly blowing it out.

The Problem Now.
Turning on the hot tap doesn't make the boiler fire up. The pilot is on and the fan appears to be working. The hot tap flow is ok/poor and then after 10/15 seconds flow gets very very slow accompanied by a rising whooshing water sound coming fron the boiler. The whooshing used to continue for 10/15 seconds before the water heated up, the whooshing would stop and the flow would get better. Now it doesn't do that, just continues to whoosh and the boiler fails to fire. Can hear 'whooshing' half way through video 3 http://uk.video.yahoo.com/video/play?vid=1799198

Turning the heating to constant doesn't make the boiler fire up either. The pilot is on and the fan appears to be working.

Other fault finding I've done: The PCB had dry/loose solder joints at resistors R1 & R2. I've cleaned & re-soldered them. The resistors themselves may have failed though? If you think they may relate to the problem I can easily replace them if you can tell me their rating.

Any ideas gents. 3 AVI's below.
http://uk.video.yahoo.com/video/play?vid=1799083
http://uk.video.yahoo.com/video/play?vid=1799120
http://uk.video.yahoo.com/video/play?vid=1799198

 

[Rob]

the fan has two speeds, does it go to full speed when a demand is made?

 

[jenicks]

Yes it does. It did fire up momentarily just when I switched it to constant just, but then stopped. The pilot is fine and the fan is operating at full speed on demand.

Same for H/W and Heating.

 

[jenicks]

.
Will check PCB & wiring again but that doesn't account for the rising whooshing sound and slow flow when the hot water tap is turned on.
.

 

[twgas]

check aps

 

[jenicks]

check aps

aps?

 

[twgas]

air pressure switch
top right hidden behind side panel IIRC

 

[jenicks]

air pressure switch
top right hidden behind side panel IIRC

I disconnected the RED hose and both HW and Heating WORK! For how long I'm not sure as I only tested for 10 seconds in case I'm not supposed to. Is that the cure to all my problems do you think? If so where can I get a switch ASAP? Can you paste me a link.

Or a red herring?

With the red hose off, am I safe to run a bath and warm the house for an hour or not.

Sincere thanks Mick.

 

[jenicks]

.
If this is the problem (please see previous post) Can anyone suggest where to get a

C6065A1093 Potterton Puma 80 Air Pressure Valve

Many thanks
.

 

[alan m 1974]

I would try cleaning the tubes out first as the aps might be ok,fan could be the fault,try blowing the tubes clear

 

[jenicks]

I would try cleaning the tubes out first as the aps might be ok,fan could be the fault,try blowing the tubes clear

Tubes are clear.

I think I'll order a complete PCB ( as it looks knackered) and the aps. I know it'll cost a bit but I've got to get it sorted.

Kids and wife are moaning.

Where can I get them from online?

Many thanks.
.

 

[bengasman]

If pulling a tube of the aps did the trick, there is something seriously wrong. You have bypassed the safety that stops the boiler from letting gas out when the fan is not working properly. Stating the obvious: this is very dangerous.
Get a pro to check and service the boiler.
you can pay for this by not buying a pcb that you probably don't need

 

[ChrisR]

If pulling a tube of the aps did the trick, there is something seriously wrong. You have bypassed the safety that stops the boiler from letting gas out when the fan is not working properly. Stating the obvious: this is very dangerous.
Get a pro to check and service the boiler.
you can pay for this by not buying a pcb that you probably don't need

 

[jenicks]

If pulling a tube of the aps did the trick, there is something seriously wrong. You have bypassed the safety that stops the boiler from letting gas out when the fan is not working properly. Stating the obvious: this is very dangerous.
Get a pro to check and service the boiler.
you can pay for this by not buying a pcb that you probably don't need

Thanks guys warning noted.
15 min ago (before your replies) I ordered a recon PCB ( it did look knackered, relays burnt, dry joints everywhere) & APS £100 all in.

I'll try them and if still no joy get someone in.

Filling the bath with kettle as we speak
All I need now is the fan belt on my s4 to let go. That'll make my week.
..
.

 

[jenicks]

..
Replaced PCB and Air Pressure Switch but still the same problem. Boiler will only fire-up if the red hose is removed from the Air Pressure Switch.

Suggestions? I've gone this far, I'd like to sort it myself if poss.

So far:
P.C.B
Air Pressure Switch
DHW Flow Switch + Microswitch
..