Yet another Potterton Suprima question!

[Steelmasons]

Would it be a grundfos UPs2 pump that was fitted??

 

[Agile]

Thanks for the photo of your boiler panel.

That does look like an original factory one as the data plate is external as shown on your replacement PCB carrier.

So it does seem that as you thought the boiler was factory fitted with the new PCB design.

The replacement PCB comes with a paper sheet quoting what the flashing light codes mean. I will see if I can find one if you have lost yours.

During 2007 I posted this in this forum which was in relation to the original PCB design.

A rather honest advisor at Potty was very helpful to me by admitting there had been a fault with the gas valves on some earlier Suprimas.

The winding tension was too tight and this sometimes caused shorted turns which reduced the winding resistance.

The effect of this was ( surprisingly ) to increase the voltage across the coil. As more turns shorted, the effect became worse and eventually blew the PCB. Just replacing the PCB would cause the new PCB to blow again if the gas valve was not changed!

Tony

 

[Agile]

This may help you! But it does not list a "10 flash"

In the manual that comes with the Siemens replacement PCB kit Potterton list a number of fault states:

Flashing red every 5 seconds is a thermistor fault

Flashing red/orange 3 times per second is a wiring harness fault

Flashing red/orange once per second indicates that incoming voltage is below 180V

Flashing red/orange every 5 seconds indicates a False Flame (we think this is a flame which is present when it shouldn’t be)

Flashing red 3 times per second indicates an air pressure switch problem or a flow switch problem (earlier Suprimas had no flow switch)

Continuous red indicates a PCB fault. According to a note on the side of the PCB, continuous red can also indicate that the Pump Live is not wired directly from the boiler or that Live and Neutral are reversed (polarity).

Flashing red once per second is lockout, normally caused by overheat or by ignition failure. If the boiler is in lockout, the instructions tell you to press and hold the reset button for more than 10 seconds then count the flashes; 2 flashes indicate that the lockout was caused by ignition failure, 5 flashes indicate that lockout was caused by overheat

 

[DP]

The effect of this was ( surprisingly ) to increase the voltage across the coil. As more turns shorted, the effect became worse and eventually blew the PCB. Just replacing the PCB would cause the new PCB to blow again if the gas valve was not changed!

Tony, again I stress that PCB will not blow as you suggest. My recomendation is that you look at the early PCB and then come back and explain how the PCB will be killed by windings that are too tight. I bet you cannot name and shame person who told you that quip.

Gas valve is not manufactured by potterton, I fail to see how someone at potterton would be qualified to check coil wire tension.

In similar vein, I had an issue with PCB in a vaillant boiler where the guy at technical help desk kept harping on that the gas valve was faulty after the PCB was replaced. When I escalated thus yo someone with knowledge on said model, the new guy admitted that they were just going by what GW recomendation was. Clearly advice give is generic bug person in front of the boiler is the one that deals with cards that he is dealt

Going back to suprima gas valve taking out the PCB, well I have checked the old PCB and am thus doubting your suggestion which I feel is based on hearsay

Bernard. I spent some 25 years working with relays and switchgear adjusting contacts, contact pressure, contact twining, lift clearance, adjustment of armatures, timing of contacts...... You name it I did it. I would like to think I know a little about relays (of course without getting a big head)

A faulty gas valve will pop the fuse before it takes out the PCB. As I have already made it clear, it will not kill the pcb, unless I need further education

 

[bernardgreen]

Bernard. I spent some 25 years working with relays and ~~~~~~~..I would like to think I know a little about relays

Failure to maintain the correct tension during the winding of coils can and does result in failure of the coil due to insulation being abraided. This occurs during manufacture if tension is too high and occurs later if tension was too low when winding.

Impedance tests normally ( should ) detect shorted turns during Quality Assurance testing. Hence windings that are over tight do not normally get into equipment. . Slack wound colis can fail after years in service when turns have been moving against each other due to changing magnetic fields.. ( transient when DC supply is switched, continuous when coil is fed with AC. )

 

[Migs73]

Would it be a grundfos UPs2 pump that was fitted??

I think it is a grundfos alpha 2. It has three speed settings, auto adapt, and a display showing the pump speed. It is currently set to auto adapt, it is hard to see the size of the pump as it is behind my hot water tank.....awkward as hell, one of the reasons I didn't replace it myself!

 

[Migs73]

Failure to maintain the correct tension during the winding of coils can and does result in failure of the coil due to insulation being abraided. This occurs during manufacture if tension is too high and occurs later if tension was too low when winding.

Impedance tests normally ( should ) detect shorted turns during Quality Assurance testing. Hence windings that are over tight do not normally get into equipment. . Slack wound colis can fail after years in service when turns have been moving against each other due to changing magnetic fields.. ( transient when DC supply is switched, continuous when coil is fed with AC. )

I think the reason my gas valve was changed was due to water damage from a storm that blew rain water into the boiler, it was across the top of the boiler as well. Bearing that in mind, it could have damaged the PCB requiring it to be replaced also. As I said before I was away from home when the repair was done.
Also, if it is true as stated before that the gas valve is controlled via a relay from the PCB, them no fault on the gas valve should affect the PCB as it is electrically isolated. A fault as described on the relay coil could damage the PCB, as that is powered from the PCB. A fault on the gas valve/solenoid could damage the relay, but would most likely blow a fuse first if the circuit is designed correctly.
That's my tuppence worth anyway!

 

[DP]

Bernard, your post throws no light on faulty gas valve possibly killing the pcb
Ins and outs of coil winding is not in dispute. I know nothing about coil winding so have no input for that topic

 

[ianmcd]

I think it is a grundfos alpha 2. It has three speed settings, auto adapt, and a display showing the pump speed. It is currently set to auto adapt, it is hard to see the size of the pump as it is behind my hot water tank.....awkward as hell, one of the reasons I didn't replace it myself!

Try setting the pump to a fixed speed , max is probably best and see how that makes your boiler behave, your boiler like most of that age were not designed to have a modern modulating pump fitted, and some boilers struggle with the pump electronics, the early Grundfoss ones did damage PCBs and needed a special supply lead to protect boiler pcbs

 

[bernardgreen]

Bernard, your post throws no light on faulty gas valve possibly killing the pcb

It was intended as background knowledge about the various failure modes that are known to have affected the reliability of some gas valve / PCB combinations.

 

[AGAS]

can u see a twelve way connector on the PCB ??

 

[DP]

Bernard, boiler in question is a Potterton Suprima. Your view is not valid for the setup. Will grant you a silver star for your view but not a gold star as boiler and gas valve failure the way you indicate not likely to happen

 

[Agile]

DP, I merely posted about what someone at Potty tech help had told me in case it was of any help to anyone at the time.

I have no need or interest to investigate it.

Virtually all of the Suprimas still in use have the new design of PCB.

 

[DP]

Thank you for responding to my question

It is sad that you do not feel the need to investigate/ look into a problem. I see that as a failing on your part as that logic is akin to wearing a blindfold. A person learns from his mistakes. Also nothing ventured nothing gained.

 

[AGAS]

can u see a twelve way connector on the PCB ??

Migs73 still waiting for an answer , never mind eh