Suprima lockout.

[rick3]

Hi, just started to have these lockout issues. Some gurgling and knocks seem to always accompany these lockouts (red light flashes). This is a brand new PCB (5111603) on a Suprima 100 and it mainly occurs right after the end of the heating period.

When heating time is over I noticed the motorized valve (honeywell 4043h) will turn immediately to the position where the spring is fully relaxed (must be the 'closed' position?). The fan is still running and everything works as normal for another 2 minutes approx.

I assume because the CH and HW valves are now closed the boiler somehow overheats and thats the reason for the lockout. The gurgling and knocks then start but calms down after few minutes when it had a chance to cool a bit. The reading in the system pressure gauge may also jump together with the knocking noise.

The red light flashes until next morning...and you have to rest it. Then it works fine for the day untill late night but once heating ends the same story starts again.

What is happening? Need ideas please.

 

[seco services]

When heating time is over I noticed the motorized valve (honeywell 4043h) will turn immediately to the position where the spring is fully relaxed (must be the 'closed' position?). The fan is still running and everything works as normal for another 2 minutes approx.

I assume because the CH and HW valves are now closed the boiler somehow overheats and thats the reason for the lockout. The gurgling and knocks then start

is the system not fitted with a bypass ?

 

[45yearsagasman]

Does sound like overheat problems from what little info you give. Pump should overrun till temp falls below 70c through a min 22mm bypass of at least 2m in length.From info I assume you have s plan system.Is pump driven from PCB?

 

[rick3]

bypass exists and open. Pump is connected to the wiring centre (not pcb).
sorry for the little info - fairly new to boilers etc.
like i said this thig only happens once heating period is over.

 

[mrgas]

Did you have a new fan fitted at the same time as the PCB?
I think you need to replacew both at the same time on the 100, but notsure of the top of my head why? maybe fan overrun?

 

[kevindgas]

Did you have a new fan fitted at the same time as the PCB?
I think you need to replacew both at the same time on the 100, but notsure of the top of my head why? maybe fan overrun?

i think it is only the 120 that has to have the fan as wel but i might be wrong

check that the pump is wired to the wiring center from the pump live in the boiler and then directly to the pump it needs to be.
you should also have a permanent live to the boiler.

 

[rick3]

well it definitely overheats, and extremely quickly.
There is no way I can touch the outpot pipe...

If I understand it correctly, once the timer reaches the end of the heating period at end of day (or manually from within the panel in the house) the 2 valves (HW & CH) both get moved automatically to close position and the pump continues to run and push the water via the bypass circle only (say for another 20 min), but the stupid boiler keeps running for some reason...

Obviously if the boiler is still fired (and it seems it is) the small amount of water in the bypass circle will overheat very quickly (1-2 minutes) and you get a lockout!

Does this sound a logical description of the problem?

If so, shouldn't the 2 valves closed only after the boiler has stopped heating??

 

[matt1e]

If so, shouldn't the 2 valves closed only after the boiler has stopped heating??

yes, one of them most likely has a sticking micro switch. well thats what my money is on

Matt

 

[rick3]

thanks Matt, can I test the microswich in any way?

for example, I just now moved the lever (on the valves) to the open side (so both valves are forced to the open position), I then go to the control panel and switch the heating off from there. But the boiler keeps on running (well I gave it 10-15 minutes and its still running)

Its as if the control panel signal to "stop heating" get only to the valves...

This solves the lockout but the boiler seem to run continuously.

Any thoughts?

 

[seco services]

have both the valves closed now ?

 

[rick3]

those valves (both) are closed automatically once the heating is stopped from the control panel. When I turn HW off at the panel the HW valve starts moving and will close. Exactly the same happens when I turn off CH (the CH valve will close). It takes around 10 seconds from the time I turn it off at the panel until they are fully closed.

... and 1-2 minutes later the overheating happens.

 

[seco services]

as matt1e said

check if the valves are still live on the orange wire.

 

[rick3]

BTW, the panel/programmer is old and it looks there is no easy way to change a battery for it. So at the moment there is no battery backup there. Can this have something to do with this?

 

[seco services]

have you checked the orange wires from the valves ?

 

[rick3]

Tested the voltages:

The orange wires from both microswitches/valves are connected to the same point (#10) in the wiring centre box.

The voltages at this point:

(1) During normal operation: Constant 240v.
(2) During lockout: Constant 240v.