Potterton profile 50e boiler help

[psarinuk]

Hi,

Another fresh problem for a monday morning
My old trusty Potterton Profile 50e boiler has just been moved to a newly extended wall in the garden (approx 3.5 meters).
The pump is still at the old location and the only thing that was moved was the two 22mm CH pipes and a new 22mm gas pipe was laid as new for future use (even though the boiler only takes 15mm).

The radiators were filled to the brim everywhere. The hot water tank was full as well before the boiler was started. The pump was also bled (central screw) before starting the boiler.

It started as normal, then gained its flame. Ran for about 2-3 minutes and then just turned off, then never came back on. The boiler surface was hot whereas the pipes were cold.

There is power at the boiler, but when I open the microswitch under the pump, there is no power there. Is it OK to connect power directly to this pump to see if it runs? Can anyone please advise the firing/ diagnosing sequence of this boiler? Does it have a fuse?

I've another plumber coming around but I just want to be armed with all the information so we can sort this quickly when he arrives.

Thank you.

 

[75pete]

You could check the fuse that lives next to the pcb and the heat over load that lives in the bottom cover. Have you got a users manual? If not you will find one on line for free.
Pete

 

[psarinuk]

Hey 75pete

Marvellous reply. I will look for the fuse, I could see the PCB lying flat at the bottom inside a cover.

How do you check the heat over load? The thermostat knob broke while taking off the boiler, so the plumber just twisted the pin (where the knob sits) manually to far clockwise.

No I've not got the user manual but would take a look online as suggested by you.

Thank you once again.

 

[75pete]

If your boiler was firing up then tripping out, it points to the over load that has tripped. Easy to reset, small cover that just drops down, look for red button then push to reset. Did you check that pump was running? simple check also, remove the screw and look and or place a pencil into hole to feel movement.
As the boiler has been moved, it could be air locked, may have to bleed at pipe joints to check. The boiler has its own drain point at the front, you could also check.
Pete

 

[psarinuk]

Great reply again pete,

The pump is not running, there was no current at "L" in the microswitch. Probably stopped by the boiler control board due to overheat/ overload.

The plumber did bleed at Flow and Return pipes at top of boiler but I would also use the boiler drain valve today as advised by you as there is a strong possiblity of air lock.

So many thanks once again from the bottom of my heart..

 

[HERTS P&D]

Over heat stat, there is a button on the bottom right under the boiler, push it in. If it only last 2-3 mins before it goes off again then it means there is an air lock.

Andy

 

[75pete]

If you do remove the drain, be ready for the possible head of water. If no water it could be just a small blockage at the drain point so again ...ready for water. Cover the bottom of the boiler to stop any water getting to the controls and switch off the supply and ensure the power supply is isolated before starting work. Go around the system and rebleed as necessary, looking for any bleed points fitted to the pipe work, expect to find some by the hot water tank.
Pete

 

[psarinuk]

75pete, hertsdrainage2010, you guys are spot on, some success!

Went home for lunch. Pressed the overheat reset (it sounded like I broke it). Started the boiler again and bingo it fired. I did not leave it running for more than 30-40 seconds each time I fired it to avoid overheating every time.

However, still disappointed at the pump. Removed the central big screw from pump and it was not running (the boiler was on). There are drips of water coming through. Tried to move the spindle with a screwdriver but it simply won't run. I've a feeling that the boiler is overheating because the water is not circulating through the boiler(since pump is not running).

There are 3 wires in the microswitch which is connected to a control board, which is then linked to the boiler/ mains. There is no power in any of the 3 microswitch wires. Can the live for pump be connected direct to mains (atleast to check that it runs)?

Any other basic ideas of checking a pump would be highly welcome.

Thanks once again. You rock..

 

[Agile]

O/H stat is on the bottom surface of the boiler slightly to the right of centre.

Push upwards.


BUT it sounds to me as if the pump has not been correctly connected to the boiler so that it controls the over run.

Tony Glazier

 

[psarinuk]

Hi Tony,

The plumber said he has not changed any connections and he has put the same connections on a new cable (which is 7 meters longer).

The pump was running fine before but its not running now as its not getting any power.

When does the pump start? What is the sequence? Is it directly connected to mains or is it controlled by boiler's PCB?
Any quick way(s) to check it?

Thanks.

 

[Agile]

Its connected to the choc block on the rear hinged PCB tray!

Or thats where it SHOULD be connected.

Starts the pump as soon as any demand for heat and continues until a while after last firing occured!

Tony

 

[psarinuk]

Hi Tony,

When the boiler was moved, the PCB and its connections were not touched. The cables were removed from a board on the wall near the pump, marked and then a new long cable was connected between the existing boiler cable and the the box/ board on the wall..

The electric tester does not light up at the control terminals for the pump (both on wall board as well the pump). Can I connect the pump's brown wire (Live) direct and see if the pump runs?

Thanks.

 

[Agile]

In these situations I never understand how an apparently gas registered engineer is engaged to move a boiler and then he leaves it NOT working???

I smell a rat!

Powering the pump from a 13 A mains socket and with a 3 A fuse in the plug top should restore normal service!

Tony

 

[psarinuk]

Leaving rats alone and just sticking to the issue:

The pump powers when I supply direct power through the switch and the boiler/ heating runs fine.

However, the pump would not turn off when the timer shuts the boiler down. So I think it needs to be wired in the same block as the power for timer.

But if I connect the pump's live with timer's live, would I achieve the pump over run from boiler after the latter shuts down?

Starts the pump as soon as any demand for heat and continues until a while after last firing occured!

the pump has not been correctly connected to the boiler so that it controls the over run.

 

[Agile]

Where you choose to think the pump should be connected is not where it ought to be!

There is only one place for it to be connected and thats the appropriate connections on the boiler so the boiler controls the pump to provide over run.

If you really had a gas reg to move the boiler then why did he not sort out any issues?

Tony