Potterton Kingfisher Mf CFL 70

[stevecaner3546]

For the last 6 years this has worked "perfectly" (new fitted by pr corgi fitter) new Danfoss 15-50 pump fitted 2 years ago - still worked perfectly.
Landis & Staefa RWB9 controller. When pressing the + 1 hour for CH both CH & HW indicators would come on and boiler fire up. When pressing + 1 hour for HW only the HW indicator wold come on - no problems. Fully pumped system with 2 x electric "zone" valves (no divertor valve).

Last Friday came home and rads were cool (Dec 17 2010) so went to press + 1 hour for CH/HW and the light were alredy on but boiler off. Turned up boiler thermostat (potentiometer) - NOTHING but fan still running. Switched all off at controller, waited 10 minutes, pressed + 1 hour for CH and both CH & HW light came on. Boiler silent for 1 min as usual then fan started then green pilot/mainburner light flashed on boiler about 3 or 4 times then stayed on and boiler lit. Went out after 10 minutes but boiler fan kept running - it usually stops completly before reignighting when temperature lowers.

Pressed RESET on controller and reset day, time then programs and copied to sat & sunday.

Boiler still running intermittently but 19/20 mins at a time but strange thing is that when pressing CH + 1 hour only the CH light comes on and the Boiler is DEAD but activating the HW + 1 hour the Boiler springs into life (may or may not continue running as above). I now have to press BOTH the HW + 1 hour AND the CH + 1 hour to get the system running as it did before I reset the programmer but...... I still have the 10/20 minute or intermittent ignition problem and the fan runs what seems continuously.

Help - it's Christmas and dammed cold. Any ideas would be appreciated as can't get anybody to even look at it until new year although one guy did come in on tuesday and said "if it ain't broke can't fix it - it seemed to be Ok at that time.....

Steve

 

[twgas]

I would suspect the CH zone valve is stuck/sticking partially open, but your post needs very careful reading as it's rather like someone talking very excitedly.

 

[stevecaner3546]

I would suspect the CH zone valve is stuck/sticking partially open, but your post needs very careful reading as it's rather like someone talking very excitedly.

Sorry about that but I'm not excited only trying to give ALL the information I can. Have followed the Potterton Fault finding flow chart and it comes down to - Thermistor -> Potentionmter -> main control unit (PCB) but when it fires up it runs normally.

Second problem now is WHY the hell has the programmer decided to separate the HW and CH from each other when using + 1hour on CH after a reset?

Steve

 

[bengasman]

Experiment with different ON PERMANENTLY combinations until you have one where the boiler actually stays on for a while.
Leave it on that setting, and check both zone valves to see if they are open. If they are not, open them manually.

 

[bengasman]

And for future reference, do not run ch and dhw at the same time if it can be avoided in any way. Running them separately has a much better performance.

 

[stevecaner3546]

And for future reference, do not run ch and dhw at the same time if it can be avoided in any way. Running them separately has a much better performance.

But - always a but...... The programmer doesn't operate the boiler in CH mode only - only whe HW or HW & CH is selected and just tested it with "on once" but it decided to switch off at the end of program 1 not the last off @ 11pm.

Weird........... this only occured after a hard reset on the controller????

Steve

 

[Agile]

You seem to have all the hallmarks of a too jumpy person who rushes into complications like a hard reset when you dont understand the problem

The way you write makes it difficult for me to even understand whats wrong.

At first I thought that the boiler was failing to run for long. You seemed to admit you had a demand from the programmer but the thought the problem is with the programmer.

You now seem to have decided to concentrate on a problem with your programmer.

I cannot conclude what your problem really is but I expects its with the boiler or a motor valve and NOT with the programmer.

The programmer does NOT start the boiler itself. It only operates motorised valves and THEY provide the start signal to the boiler.

[ And before you start jumping again those motor valves do NOT give a signal when the lever is used! ]

Tony Glazier

 

[bengasman]

And for future reference, do not run ch and dhw at the same time if it can be avoided in any way. Running them separately has a much better performance.

But - always a but...... The programmer doesn't operate the boiler in CH mode only -...

Time to invest in better controls.

 

[stevecaner3546]

And for future reference, do not run ch and dhw at the same time if it can be avoided in any way. Running them separately has a much better performance.

But - always a but...... The programmer doesn't operate the boiler in CH mode only -...

Time to invest in a better controls.

Sorry my new friend.

Problem 1 - boiler seemed to only run for 10 - 20 mins. Programmer not touched.

Problem 2 - as above but when boiler wasn't alight the fan keeps running as though the main gas valve should be open but main burner is not lit.

3 - Local guy come in and checks system declareing it Ok - valves opening and closing - pump running and "boiler alight" Can't fix it - not broken. 2 hours later it reverted to Problem 1 mode.

Turning the boiler thermostat up sometimes "click" and boiler lit more often though "nothing" so I switch the system OFF on the controller and press +1 hour on CH (both CH & HW lights come on and boiler lights up as normal - runs for about 20-30 mins then main gas burner goes out but fan keeps running (I don't think it should?) so I cancle the + 1 hour and wait 20-30 mins and again press + 1hour CH and both lights come on.

Ran on and off Wednesday and lived with it but got so peed off I went to reprogram it to at least warm us up this morning but for some strange reason the HW light wouldn't go out so in desperation I stuck a ball point in the RESET button and reset time and program then realised that I missed the DAY setting for time and the controller thought it was Monday so I reset again and set it correctly to 10am on Sunday. Ran for a short time but after the first reset when having the CH on only it usually runs both the CH & HW lights but now only the CH light is on but the boiler is DEAD. When I switch to HW only it fires up. When I set it for both we go back to Problem 1.

Steve

 

[twgas]

as I dont like to see people cold, especially, at this time of year, I'll try to help. but I need straight answers to simple questions (to save confusion).

Start by turning HW(hot water) AND CH(central heating) off at the programmer.
Turn the room 'stat up to the highest possible setting.
Turn CH on at prog.
does the CH valve move(open) and does the boiler light up.

 

[stevecaner3546]

as I dont like to see people cold, especially, at this time of year, I'll try to help. but I need straight answers to simple questions (to save confusion)..

Actually we arn't cold as I am "limping" it by turning it off and restarting after 1/2 hour.

Start by turning HW(hot water) AND CH(central heating) off at the programmer..

This is what the engineer did on Tuesday but I'll do that in the morning again.

Turn the room 'stat up to the highest possible setting..

Max temp is 27C and we set that on Tuesday as well but will do tomorrow.

Turn CH on at prog..

Must say here that although the red light on the controller is ON the boiler is DEAD until the HW is on - weird but will check in the morning.

does the CH valve move(open) and does the boiler light up.

He checked this too but you must remember that the programmer was working with both HW and CH coming on with the CH + 1 hour button.

Steve

 

[AlanE]

Must say here that although the red light on the controller is ON the boiler is DEAD until the HW is on - weird but will check in the morning.

That's not really that wierd if you know how the programmer internals work.

The indicator light on the programmer front is connected to the same point as the relay in the programmer so if the elecrtonics deem it time for it to operate the CH, say, they provide power to operate the relay and indicator. Now if the relay is faulty the programmer will show the programmer has switched the boiler on whereas, because of faulty relay, in pratice it hasn't!!

That fault you describe could well be a faulty programmer but that can only be confirmed by measuring output voltage of programmer. Faulty wall stat can cause same symptoms.

 

[Agile]

Alan, are you convinced the CH valve is creating a call for heat?

Tony

 

[stevecaner3546]

Must say here that although the red light on the controller is ON the boiler is DEAD until the HW is on - weird but will check in the morning.

That's not really that wierd if you know how the programmer internals work.

The indicator light on the programmer front is connected to the same point as the relay in the programmer so if the elecrtonics deem it time for it to operate the CH, say, they provide power to operate the relay and indicator. Now if the relay is faulty the programmer will show the programmer has switched the boiler on whereas, because of faulty relay, in pratice it hasn't!!

Strange thing tonight - system controller on AUTO for HW & CH bot at same time. Boiler thermostat set to just above 1/2 way (pretty cool really compared to 3/4 setting normally used this weather). Boiler fired up @ 16:00 as it should and all the rads were hot(ish) at 18:50 sensed I was colder than I was 20 mins earlier so I went back and heard the boiler fan running (should have been off if the boiler was off) switched controller to all OFF and boiler shut down. pressed + 1 hour for both HW & CH and boiler fired up as it should and ran - rads Hot.

Went back an hour later and boiler dead quiet - both HW &CH lights on no controller so I moved the settings to Auto and went back to watch TV. 22:00 went back to kitchen - rads cold, room stat @ 25C boiler OFF controller showing that both CH & HW should be running. Turned boiler thermostat up to 3/4 and it sprung into life. Went to bed @ 11:25 - rads hot or warming up. - controller switched off @ 22:30.

Will see if strats up @ 05:30 in the morning - probablywill but will it keep running and why does the fan keep running when the boiler is supposed to be OFF - controller should be calling for heat as should the room stat and the rads are cold(ish) but HW very hot (stat set @ 120F or 50C)

If the water gets hotter than it should this should simply close the HW valve leaving the CH valve open.

Steve

 

[Agile]

You seem to be fixated with your controller.

You also switch your controller OFF and then instead of back to auto you decide to create a different situation by using the boost + 1 hour instead. To diagnose faults you have to be consistent in your tests and not introduce new senarios.

I am still not convinced of any fault apart from the boiler failing after about 20 min, but earlier you seemed to think it would run normally for hours on end if you selected a particular setting on the programmer.

If I ignore your own thoughts, are you able to view the pilot flame when it starts up normally and also when its in the fault condition?

Tony