Potterton Profile Boiler - Temp Sensor Kicking In??

[kevplumb]

yes
put a small screwdriver in the hole and make sure the shaft turns



as suggested make sure the valves are open
and which direction it is pumping (arrow on case )

 

[lulu73]

the shaft moves freely when turning with a screwdriver, but it makes a horrible racket when turned on.

By switching just the hw on as has been suggested, the boiler still turns itself off after a couple of minutes.

And the direction of flow according to the pump is downwards (!) and the writing is upside down.

 

[kevplumb]

are the valves open
its running dry

 

[lulu73]

well, upon checking the pump valves, one of them (the top one) is actually spinning freely (its a gate valve type one).

Could this be a (THE) problem...?

 

[kevplumb]

probably sheared inside new valve

 

[lulu73]

Looks like I'm going to have to drain it down again then

As it is the one on top i.e the one that is supposed to be letting water into the pump, could I have damaged the pump by running it dry?

Thank you all for your input and help. Much appreciated.

 

[kevplumb]

probably the water lubricates the bearings

 

[Agile]

If the pump was working AND pumping water then he would get either heating or hot water regardless of the position of the mid pos valve.

Wrong.
If the valve does not get driven to its correct position, it will not make the safety microswitch, which will not signal 'OK' to the boiler, which will then shut itself off to after a short predetermined time to protect itself and the system.
Just like the symptoms he has described.

Whilst the mid posn valve could by chance have failed inbetween the three positions, if that had happened there would be no call for heat and the boiler would not come on at all. He already said the boiler came on for a "couple of minutes".

Even if the top valve was closed then water should find its way around the system through the bottom valve. I suspect BOTH valves are closed. Take the pump out and check!

Tony Glazier

 

[lulu73]

Drained system, took out pump, top valve was closed, bottom was only half open.

Replaced both anyway, re-used same pump and system is all ok now.

Thanks again

 

[chrishutt]

Check pump valves are open

Well done Agile.

 

[Agile]

Yes Chris, but I said that a week ago!

One wonders he did not check it the same day instead of talking about other things!

Tony