Puma 80

[Softus]

The unreliability of the Puma PCB originates because the holes drilled in the substrate are too large and do not hold the pin in place tightly.

I concur.

This results in the pin being held by the solder joint which fails as a result of thermal cycling...

I concur again.

...and insertion/removal of the plugs.

I disagree with this part. In principle, you're right, and the precaution of minimum disturbance is generally a good one, but I still believe that the advantage of having the board on a table top, under a strong light, with two hands free, outweighs any risk that the act of removal exposes a latent fault in a joint. If no components are damaged, then it's not a big job to check resistance across any suspect joint and resolder anything that is poor.

 

[park]

DHW flowsitch - red light on PCB?

Hi checked that, yes the red light is on when hot tap run.
Also checked the flame, that increases in height when hot tap opened up, so what next

 

[Softus]

If it's not an electrical problem then in all likelihood you have a faulty diverter valve.

so what next

 

[park]

If it's not an electrical problem then in all likelihood you have a faulty diverter valve.

so what next

If someone had altered the D.H.W. Manual Flow Restrictor would that cause the problems with the hot water tap running cold

 

[Softus]

I don't think so, but the auto flow regulator would be acting if the output temperature is too low.

I believe the MFR acts only to reduce the flow in addition to the AFR, so its effect would be to increase output temperature, if anything, not reduce it.

Do you suspect that the MFR setting has been altered? Is someone other than you working on this appliance?

 

[Agile]

...and insertion/removal of the plugs.

I disagree with this part. In principle, you're right, and the precaution of minimum disturbance is generally a good one, but I still believe that the advantage of having the board on a table top, under a strong light, with two hands free, outweighs any risk that the act of removal exposes a latent fault in a joint. If no components are damaged, then it's not a big job to check resistance across any suspect joint and resolder anything that is poor.

Another part of the problem is that the plugs onto the PCB grip the PCB pins very tightly.

Thats good in theory with with the pin retention being so poor merely a single connection of the plug when a new PCB is fitted can cause a solder joint to fail. Acoperson did just that recently!

Tony

 

[park]

I don't think so, but the auto flow regulator would be acting if the output temperature is too low.

I believe the MFR acts only to reduce the flow in addition to the AFR, so its effect would be to increase output temperature, if anything, not reduce it.

Do you suspect that the MFR setting has been altered? Is someone other than you working on this appliance?

No no-one else is working on the appliance, is the MFR not set at the factory to the correct flow rate?
If someone has opened up the MFR and increased the flow rate through the unit prior to me getting involved, would that not tend to reduce the temperature of the hot water

 

[Softus]

No no-one else is working on the appliance, is the MFR not set at the factory to the correct flow rate?

I expect that it is.

If someone has opened up the MFR and increased the flow rate through the unit prior to me getting involved, would that not tend to reduce the temperature of the hot water

I've never tried, but I suspect not, because the the auto regulator would still regulate.

 

[park]

I've never tried, but I suspect not, because the the auto regulator would still regulate.

Is the auto flow regulator not built in to the cold water supply cock or valve, I assume that is supplied by the manufacturer, what if that had not been fitted.

 

[Softus]

Forgive me if this sounds at all unkind, but some of what you're saying is just crazy talk.

I don't understand your motivation to hypothesise about some really quite unlikely things. Are you suggesting that the user of the appliance has never had a correct DHW service?

It's hard enough diagnosing a fault over the Internet, and it would be much easier for you to diagnose by standing next to the boiler and working through, systematically, eliminating possible causes. Until you've eliminated the diverter valve (which is a commonly failing component), I, as they say on Dragons' Den, am out.

 

[park]

Forgive me if this sounds at all unkind, but some of what you're saying is just crazy talk.

I don't understand your motivation to hypothesise about some really quite unlikely things. Are you suggesting that the user of the appliance has never had a correct DHW service?

It's hard enough diagnosing a fault over the Internet, and it would be much easier for you to diagnose by standing next to the boiler and working through, systematically, eliminating possible causes. Until you've eliminated the diverter valve (which is a commonly failing component), I, as they say on Dragons' Den, am out.

I asked a straight forward question "is the automatic flow restrictor built in to the cold water supply cock supplied with the boiler by the manufacturer, I thought that I was looking at simple things before resorting to the diverter valve.

 

[Softus]

Once again, you're looking at unlikely things, before looking at the diverter valve.

You started out asking about the wax capsule - IMHO you should go in that direction.

 

[park]

Once again, you're looking at unlikely things, before looking at the diverter valve.

As I said I asked a question regarding the automatic flow regulator, is it built in to the cold water supply cock, or I will add this, is there another AFR some where in the boiler.

You started out asking about the wax capsule - IMHO you should go in that direction.

Yes that is correct but I am now not sure that is the problem, if you remember I did indicate that if the heating was on when the hot water tap was turned on, then the hot water was OK

 

[Softus]

You started out asking about the wax capsule - IMHO you should go in that direction.

Yes that is correct but I am now not sure that is the problem

...if you remember I did indicate that if the heating was on when the hot water tap was turned on, then the hot water was OK

...hot water OK when heating on ?

What does "OK" mean to you? What temperature? What flow? Is it consistent? For how long did you run it?

 

[park]

What does "OK" mean to you? What temperature? What flow? Is it consistent? For how long did you run it?

I always thought that OK meant that some thing was OK, acceptable may have been a better term. I have not measured the flow rate or the temperature, but I do know the difference between hot/cold, time scale would be approx 5 min.
How ever you have still not answered my question is the AFR built in to the cold water supply cock, provided by the manufacturer