I have a Potterton Suprima 30 in a five years old house. Last year the PCB had to be replaced due to the system constantly going into lockout.

6 months after the (not cheap) PCB was replaced, the Boiler is acting up again. The system randomly goes into lockout, but the reset button sometimes works, soemtimes doesn't.

Another strange symptom that has started happening a couple of times is that the Boiler has on a couple of occasions come on all by itself late at night when the heating and hot water timers have not even been set to be on.

Also, the redirector (i think that is what it is called - it is the little black box under our water tank) occasionally makes a buzzing noise when the boiler should be on but won't come on.

Today, I cannot get the boiler on at all. Pressing reset on and off all day has done nothing for me.

Can anyone advise what to do please? Am I looking at another costly engineer visit?

Thanks

Peter Rising, April 2007

what is the pcb

derek, January 2016

the reset button was hanging down so i tried to push back up but the steel connectors touched of the steel body of boiler and there was a big flash. boiler stopped working as you can imagine so i replaced fuse but now its says lockout there is a noise from boiler but it's not igniting. Help

brian, January 2014

I've just replaced pcb, 2 motorised valves, thermostar and timer ... but boiler still does not work! The light stays orange, sometimes the green flashes and sometimes it fires up ... then it dies again and back to orange. It's freezing!!! I've had few repair men and it has cost me a fortunate ... can anybody help.

moonbeam, January 2013

There is a Suprima Emergency repair CD on eBay...

Harry Radnapp, December 2010

hi please can anyone tell me why my potterton suprima will not fire up it goes throu the motions and trys to ignite but fails to as if there is no gas there for it it trys twice then goes to red iv tried the pcb board on a friends unite and it fires up fine cheers ste

steve, November 2010

ive got a suprima 30, replaced pcb year ago everything ok until today.the boiler lights up makes a fizz sound for few minutes then starts banging as if being hit with a hammer.then cuts out does this everytime can anybody please advise me

shaun derbys, November 2010

the reason the boiler has a mind of its own seems to be the motterized valve is at fault (the redirector) its is a common fault to do with the micro switch in the valve.

mike, June 2008

I repair many boilers and the suprima is well known for going into lockout and not starting.
The Suprima is very sensitive to water flow and will lockout very quickly if the pump fails or if the motorised valve is shut. The programmer/Timer controls the motorised valve and the boiler should not come on if the pump is not powered.
If the boiler is switched ON after a long time of being OFF (1 hour say) and it does startup for a while, touch the pump body after a few minutes to check how hot it is. It should be cool to the touch. If it is very hot, the pump is shot and shoild be replaced.
These are the other checks you should make:
Remove the cover of the boiler - On the heating flow pipe quite high on the left hand side of the boiler, is located the overheat stat and the casting sensor above it. The overheat stat will cut power to boiler if it has tripped and the casting sensor may just cause the boiler to lockout. Quite often, people replace the PCB when the real fault is the casting sensor.
The casting sensor reports the temparature of the heating pipe to PCB. If the sensor is faulty and reports the the pipe is hotter than it is, the boiler may pull the plug and force the boiler to go into lockout. This is a safety feature to ensure the water does not become dangerously hot.
Testing The Casting Sensor:
Make sure all power to boiler is switched OFF.
If you have a multimeter, you can test the casting sensor by setting the meter to the 20KOhm range or higher and place the probes across the sensor terminals. The expected reading should be around 14KOhms at normal room temparature..

Really both the casting sensor and overstat should be changed together.

I hope the information was usefull

Joseph Mackintosh, April 2008

I have had the same problem on a Suprima 50.
Probably the same board.

i had it installe about 10 years ago and after about 2 i started getting the problems. called a boiler guy in or a service he said the pcb need to be replaced.

I checked on the net and decided to fix the pcb my self - i'm a technician-

The Boards area bad design. The solder joints can go dry and just touching them up with fresh solder fixes that.

I found that some of the tracks on the pcb were lifting and going open circuit. Specialy between two of the diodes on the board there is normally discolouration around them on the board. due to heat.
i was able to solder on a single core piece of wire to by pass the faulty circuit.

This has solved my problem. It started acting upagain recently. i found that the solder on my repairs had gone dry too so touched it up again.





Q----Another strange symptom that has started happening a couple of times is that the Boiler has on a couple of occasions come on all by itself late at night when the heating and hot water timers have not even been set to be on.-----

A:on some systems there is an over riding thermostat that will override everything and turn on the boiler if the temp drops to freezing-- check that its not set too high.

Q----Also, the redirector (i think that is what it is called - it is the little black box under our water tank) occasionally makes a buzzing noise when the boiler should be on but won't come on.----
A. One of the symptoms of the dodgy pcb is that the relay on the board is not gettting the signal to switch off the pump. it maybe that.



Q------Can anyone advise what to do please? Am I looking at another costly engineer visit?------

There are options. If you are anyone you know is handy with a soldering iron and can recognise faulty circuits and soldering then have a go.

Be careful though--- you MUST switch off the main power to the boiler to fiddle with the pcb.

Its best to remove it to work on it.

Cheers

Hope that helps.

Rory O'Gorman, January 2008

I also hav this boiler but nevr had problems with it before and it has been the best boiler for over 10 years

Chris, April 2007

The "redirector" is a motorised valve which has either one or 2 microswitches in it. These microswitches, in conjunction with your room thermostat, cylinder thermostat and programmer, turn the boiler on. This is probably the problem.

You can usually change only the head of the valve (actuator) i.e. no wet plumbing involved. Cost £35-£50

e.g. http://www.invensyscontrolseurope.com/NR/rdonlyres/6FD690B6-A315-4EF2-81A3-32C983351874/0/D42_4DraytonMotorValves.pdf

http://www.keeptheheaton.com/acatalog/Honeywell_Diverter_Valve.html

I depends on the make/model of valve that you have.

Cathy, April 2007

Yes, as the guys say, most likely PCB problem, sort it with Potterton.

George, April 2007

Potterton have recently been criticised on Watchdog for their poor PCBs. Give them a call on 08706 060780. They are currently sorting out the lockout problem for free. If nothing else you should try and reclaim the money you spent on the replacement board.

Rob, April 2007

Get in touch with potterton as they are replacing the boards for free at the moment as they have had a load of faulty ones , one of my customers just had it done for free because their boiler kept going into lockout

carl janizzewski, April 2007