Potterton Suprima going on and off

[richig]

I have recently moved into a house with a Potterton Suprima 30 boiled (non condensing) from 2000. The boiler heats the CH/HW fine and always fires first time and has been regularly serviced however I have noticed the following.

When the hw is heating up, towards the end when the cylinder is about hot enough the boiled goes off then comes back on after several minutes. This can happen a couple of times before the boiler switches off completely.

The boiler also sometimes switches off for a minute or so and back on when the CH is on. I know the stat is still calling for heat as the room has not reached temeprature.

I have guessed myself that the boiler itself has reached temeperature and switfched itself off despite the cylinder or room stat still calling for heat. I guess the boiler then cools a little and comes back on as there is still call for heat?

Is my assumption correct.

(the boiler has always done this for the time we have owned the property and was last serviced 8 months ago

 

[oph]

Sounds like all systems go.

 

[dominoman]

Sounds like it is operating as it should.

If the water returning to the boiler is hot enough (measured by the thermister on the return pipe) then the boiler will shut off, even if there is still a call for heat from the room thermostat or tank.

The pump should keep circulating the water. Once it cools a little the boiler will fire up again.

 

[oph]

Sounds like it is operating as it should.

If the water returning to the boiler is hot enough (measured by the thermister on the return pipe)

You sure about that...........

The Suprima has an overheat stat and boiler stat........and both of those are located on the flow not the return

 

[hazetimesfive]

the suprima also has a pcb that when the water is cold and really needs to be heated will just die for no reason whatsoever and sit there flashing a red light at you to make you feel warmer.

 

[Biggles..]

The sequence the red light flashes can be transcribed from morse code to read either "congratulations you own a crap boiler" or " please put me out my misery and throw me into a skip because I'm a waste of money"

A flashing green light normally spells out "haha tricked you, I'm still not working properly!"

 

[Scarum]

The sequence the red light flashes can be transcribed from morse code to read either "congratulations you own a crap boiler" or " please put me out my misery and throw me into a skip because I'm a waste of money"

A flashing green light normally spells out "haha tricked you, I'm still not working properly!"

True but getting your gas man to replace with upgrade PCB (part number 5111603) will resolve this and add many more years to the boiler's life.

OP's original description sounds like normal behaviour.

 

[dominoman]

True but getting your gas man to replace with upgrade PCB (part number 5111603) will resolve this and add many more years to the boiler's life.

OP's original description sounds like normal behaviour.

Exactly what I did. Got a refurbed one cheap on eBay. Boiler works perfectly again now. I'm hoping to get another few years out of mine yet.

 

[Biggles..]

Hope you did the harnesses well.