Strange fault with Drayton programmer

[merlinradioltd]

Weird one this. 3rd UP2 Programmer fitted by BG since January to replace an older version of the same type, which was a pretty basic model..(can't remember the model no). Anyway this one is a Drayton LP722 rebranded as a UP2 which should be a direct match to the existing wall plate..wired as live and neutral and then 1 is HW off, 2 is CH off and 3 HW on and 4 CH on...(so far so good). Each time the programmer fails, the effect is no CH unless HW is selected. Take the programmer off the wall plate and put it back on and it works for a few days. The wall plate has been changed as well as it was a suspected bad connection on the programmer connection pins. Fit a brand new programmer and all is well for say a month and then the same symptoms start again.

Although changing the programmer clears the fault for say a few weeks, so does taking the original off the wall plate and putting it back on....that works for a while.

Boiler fine, plenty hot water and great heat from radiators. Just when working as a twin channel this odd effect occurs. Motorised valves operating correctly and BG has changed the valve heads three times and replaced the room stat but can't pin the fault down. Back plane links set for independent, 24 hr prog and pumped system.Wiring on SM1 wallplate all ok and connections solid.

This is annoying, as when this happens the only way to get the boiler to fire up and provide the CH is to switch the HW on or I suppose would have to have the HW and CH to set to exactly the same times and lose the independent control which is not clever.

My theory so far is that the programmer is a pretty poor fit with the wallplate and the pins on the programmer seem to lose contact with the wallplate from time to time and the very act of taking the unit off and refitting might be just getting an intermittent good low resistance connection......Totally baffled.

 

[telectrix]

i would tend to agree with your diagnosis of poor contacts.

 

[sedgy34]

Reoccuring problem!!
Have they changed the solenoid valve on the pipe were the zone valve sits on top

 

[merlinradioltd]

Reoccuring problem!!
Have they changed the solenoid valve on the pipe were the zone valve sits on top

Not as far as know...where would this be? It's a small 3 bed semi so no "zone" as such...just a a single motorised valve and two feeds out, HW, CH or both. My other theory is about what is "inside" the programmer. Can it handle the switching current for boiler and pump etc. Are there internal contacts in the programmer sticking after a while....The oldest programmer was a basic Horstmann which ran for a good few years, superseded by a solid state...which was fine until January when it started tripping out my main RCD, a substitute with a newer Drayton version (which has boost) cleared that fault and everthing seemed fine for a month until it started this caper....All OK for about 4 weeks, then it started and so far 4 visits by BG since then, usually about 4 weeks apart....can't find the problem, which is always instantly cured by changing the programmer or simply taking it off and putting it back on the wallplate again....(Could be some kind of internal reset?...albeit it has a continuous clock which sets automatically when the clocks change in Spring and Autumn).....again baffled. I am thinking of changing this unit for a different make in the hope that I can nail this once and for all....Any recommendations gratefully received.

I have a Drayton compatibility pdf on wiring outputs anyway

 

[sedgy34]

Don't think it's the programmer if you have changed it already
try getting the 3port valve plate changed its fixed to the pipework under the head of the valve

 

[merlinradioltd]

They have replaced the electrical side of this TWICE but NOT the valve in the pipework. Could be sticking?.......Bet they are not to keen to do this as this could involve a drain down......hours of labour etc?.....Will need to get the inspection hatch open as they are coming back on Thursday with a Service Manager to see what they can do.

 

[snowhead]

When it fails, try turning off the power to the boiler/programmer and leave the programmer alone.

What gas boiler is it?

 

[PC Electrics]

Typical BG: diagnosis by guesswork!!

When I was a warranty engineer for LR/Jag it was obvious some dealers were using the same methodology on the cars! It rarely works.

 

[merlinradioltd]

When it fails, try turning off the power to the boiler/programmer and leave the programmer alone.

What gas boiler is it?

Glow worm FuelSaver MK2...bog standard hang on the wall,balanced flue, pumped system...Hot water cylinder in a cupboard, two channel electronic programmer, standard radiators without TRV's and an electronic room stat....Boiler 100% and delivers great heat and ho****er and passes emission tests and is serviced annually...so gas and water side A1.....now working again OK, but every so often throws a wobbly and I have to frig about to trick the CH to come on (pump run and boiler fire up) by messing about with the HW programme side of the controller....PUT HW on permanently and the CH will come on...leave it a while..put HW back on timed and things might be OK for a few days.......really annoyiing.....if really wont't come on, take the Drayton off the wallplate and put it back on good and tight and this might be fine for a week say.

No confidence in the "maintainer" coming in to faff about, as they are now in negative equity on the maintenance contract and will be dragging their heels in getting to the bottom of this small but annoying fault.Again all seems coincidental in replacing the programmer with a revised/updated version, even though the pinouts seem to be the same.......Nice tutorial this one...will keep you posted.

 

[merlinradioltd]

When it fails, try turning off the power to the boiler/programmer and leave the programmer alone.

What gas boiler is it?

You could have a point here!!!!.....when I have been taking off and refitting the programmer to the wallplate I have of course been turning off the power to the boiler/programmer to do just that!.......Therefore I might be kidding myself on here and what I might be doing is "rebooting" the programmer.....as the old adage...when all else fails, switch it off, leave it a few seconds and switch back on.........a bit like my SKYBOX!!!!.....?

 

[merlinradioltd]

My other theory which might be applicable to this is perhaps a spike/high inrush current during the pump startup might be having an effect on the programmer (which the older version was immune to) and by switching on and off at the electrical fused spur, I am actually clearing a programme error on the programmer....Will give this a try and cautiously optimistic that this might be the right track.

 

[Strima]

They have replaced the electrical side of this TWICE but NOT the valve in the pipework. Could be sticking?.......Bet they are not to keen to do this as this could involve a drain down......hours of labour etc?.....Will need to get the inspection hatch open as they are coming back on Thursday with a Service Manager to see what they can do.

If they take the valve off and replace it them it would be worthwhile to fit isolator valves to save draining down the system when it fails on 30 years time. A drain down and flush could be on the cards to get rid of any crap in the system, the whole lot may have acquired a chunk of magnetite stopping the valve from operating fully. Does the valve operate fully?

I could be talking out of my arse but would induced currents have an effect on the new programmer?

 

[merlinradioltd]

OK, as an electronics guy, you can get nice transient spikes on the mains when a pump fires up...never a problem with electric/mechanical time switches, programmers, but when you introduce solid state/processor controlled systems they are more susceptible to funnies (same as computers, hence surge protection on trailing sockets under desks)....the motorised valve operates smoothly and a while back a year ago, the pump was changed and the water is crystal clear..This is Scotland and it is a sealed system and no limescale or anything like that up here. It's behaving today and when it plays up again I will switch the supply on and off and see if it clears...It could just be that this particular version of the programmer is susceptible and simply switching on and off seems to "cure" this odd situation.....We shall see....many thanks for all advice given on this forum.

 

[merlinradioltd]

I live a simple life, work from home, don't actually need a super duper programmer. I am thinking of fitting a simple little surface box in parallel to this unit with 2 switches....one for HW and one for CH...pick up the connections from the wallplate and switch a live to pin 3 HW and pin 4 CH....I want control of my own heating and hot water and switchable when ever I wish..the CH routed through the wall stat, simple as that. Can have either or both.

 

[truckster]

Just a thought ...is the back plate fixed flat, the plastic plates can and do flex causing connection problems and it always seems to be the heating side.

 

[JD6400]

You have not got quite the same faults as what was probably the most annoying problematic job i have ever had since becoming a sparks but this may help ?
It was a boderous boiler (complete and utter useless unhelpful ----ers on their technical side !) run with Honeywell 2 and 3 ports along with a Drayton 2 channel controller .
The problem on this one was every so often the heating would just run on , no matter what you did at the controller and stat .
From memory it it would happen if both heating and hot water were selected and if the hot water became satisfied before the heating then the heating would never stop no matter what you did to it .
I honestly stripped the complete control circuit and re connected it from scratch over 12 twelve time on 8 different visits , it was made worse by the fact it had all come about because they had just had thermal solar installed with the new boiler a controller and valves so this made me question what we had done , so many times ( along with the inept moron at boderous ) !
I eventually called honeywell technical , who instantly said that it was a bit of a design fault on only certain boilers that will allow them to fire up on stray voltage and not just the 230v switch live that you would expect they needed to do it , the remedy was to put a little ( i think ) capacitor between Live feed in and sw live out on the zone valve as they never truly shut down and can allow around 30v through even when idle , if configured in a certain order !
The Honeywell technical chap even sent several photo copy's of the wiring diagram on how to do it and a handful of capacitor's for free !!!
Maybe worth a phone call to them if you have honeywell valves ?!

 

[sedgy34]

Heating is the easiest thing in the world

 

[merlinradioltd]

Just a thought ...is the back plate fixed flat, the plastic plates can and do flex causing connection problems and it always seems to be the heating side.

Yes this has been an ongoing issue!...BG fitted a wall plate, but the wall is tiled. There was not enough tile behind the wall plate to screw the plate flat and solid to the wall...hence the 1st bodge they did with cardboard packing (from the box the controller came in!)....which fell out as the wallplate moved easily when attached to the programmer. Bodge 2 was where they were supposed to fit a proper back box (Drayton accessory) to fit the wallplate to the tiles and came to do it and forgot the part....BUT they had an old patress box in the van......which they sawed up to get two bits of plastic to act as spreaders across the gap in the tile..to get the wallplate to sit in such a manner as to connect "properly" to the controller......(you could not make this stuff up!!!!.)......I have never seen the likes if this before....At the moment it is working as I have taken the programmer off and refitted to make it as tight as it can be.....They are turning up tomorrow....probably to agree with me and will no doubt say that they need an accessory to cover the gap in the tiles (since the original Horstmann days)....although for past few years I have lived with an annoying hole in the wall under the last programmer....As an engineer I cannot for the life of me be convinced that the csa of these little pins trying to make contact with the wallplate can sufficiently have a low enough resistance or current carrying capacity to provide any degree of long service.....bad design as far as I can see and I reckon it IS the plate bending or contracting and expanding in a hot kitchen......We shall see......if all else fails I will show them the door and sort out a permanent fix myself.

 

[Britmanuk]

Weird one this. 3rd UP2 Programmer fitted by BG since January to replace an older version of the same type, which was a pretty basic model..(can't remember the model no). Anyway this one is a Drayton LP722 rebranded as a UP2 which should be a direct match to the existing wall plate..wired as live and neutral and then 1 is HW off, 2 is CH off and 3 HW on and 4 CH on...(so far so good). Each time the programmer fails, the effect is no CH unless HW is selected. Take the programmer off the wall plate and put it back on and it works for a few days. The wall plate has been changed as well as it was a suspected bad connection on the programmer connection pins. Fit a brand new programmer and all is well for say a month and then the same symptoms start again.

Although changing the programmer clears the fault for say a few weeks, so does taking the original off the wall plate and putting it back on....that works for a while.

Boiler fine, plenty hot water and great heat from radiators. Just when working as a twin channel this odd effect occurs. Motorised valves operating correctly and BG has changed the valve heads three times and replaced the room stat but can't pin the fault down. Back plane links set for independent, 24 hr prog and pumped system.Wiring on SM1 wallplate all ok and connections solid.

This is annoying, as when this happens the only way to get the boiler to fire up and provide the CH is to switch the HW on or I suppose would have to have the HW and CH to set to exactly the same times and lose the independent control which is not clever.

My theory so far is that the programmer is a pretty poor fit with the wallplate and the pins on the programmer seem to lose contact with the wallplate from time to time and the very act of taking the unit off and refitting might be just getting an intermittent good low resistance connection......Totally baffled.

 

[Britmanuk]

Weird one this. 3rd UP2 Programmer fitted by BG since January to replace an older version of the same type, which was a pretty basic model..(can't remember the model no). Anyway this one is a Drayton LP722 rebranded as a UP2 which should be a direct match to the existing wall plate..wired as live and neutral and then 1 is HW off, 2 is CH off and 3 HW on and 4 CH on...(so far so good). Each time the programmer fails, the effect is no CH unless HW is selected. Take the programmer off the wall plate and put it back on and it works for a few days. The wall plate has been changed as well as it was a suspected bad connection on the programmer connection pins. Fit a brand new programmer and all is well for say a month and then the same symptoms start again.

Although changing the programmer clears the fault for say a few weeks, so does taking the original off the wall plate and putting it back on....that works for a while.

Boiler fine, plenty hot water and great heat from radiators. Just when working as a twin channel this odd effect occurs. Motorised valves operating correctly and BG has changed the valve heads three times and replaced the room stat but can't pin the fault down. Back plane links set for independent, 24 hr prog and pumped system.Wiring on SM1 wallplate all ok and connections solid.

This is annoying, as when this happens the only way to get the boiler to fire up and provide the CH is to switch the HW on or I suppose would have to have the HW and CH to set to exactly the same times and lose the independent control which is not clever.

My theory so far is that the programmer is a pretty poor fit with the wallplate and the pins on the programmer seem to lose contact with the wallplate from time to time and the very act of taking the unit off and refitting might be just getting an intermittent good low resistance connection......Totally baffled.

Weird one this. 3rd UP2 Programmer fitted by BG since January to replace an older version of the same type, which was a pretty basic model..(can't remember the model no). Anyway this one is a Drayton LP722 rebranded as a UP2 which should be a direct match to the existing wall plate..wired as live and neutral and then 1 is HW off, 2 is CH off and 3 HW on and 4 CH on...(so far so good). Each time the programmer fails, the effect is no CH unless HW is selected. Take the programmer off the wall plate and put it back on and it works for a few days. The wall plate has been changed as well as it was a suspected bad connection on the programmer connection pins. Fit a brand new programmer and all is well for say a month and then the same symptoms start again.

Although changing the programmer clears the fault for say a few weeks, so does taking the original off the wall plate and putting it back on....that works for a while.

Boiler fine, plenty hot water and great heat from radiators. Just when working as a twin channel this odd effect occurs. Motorised valves operating correctly and BG has changed the valve heads three times and replaced the room stat but can't pin the fault down. Back plane links set for independent, 24 hr prog and pumped system.Wiring on SM1 wallplate all ok and connections solid.

This is annoying, as when this happens the only way to get the boiler to fire up and provide the CH is to switch the HW on or I suppose would have to have the HW and CH to set to exactly the same times and lose the independent control which is not clever.

My theory so far is that the programmer is a pretty poor fit with the wallplate and the pins on the programmer seem to lose contact with the wallplate from time to time and the very act of taking the unit off and refitting might be just getting an intermittent good low resistance connection......Totally baffled.

Weird one this. 3rd UP2 Programmer fitted by BG since January to replace an older version of the same type, which was a pretty basic model..(can't remember the model no). Anyway this one is a Drayton LP722 rebranded as a UP2 which should be a direct match to the existing wall plate..wired as live and neutral and then 1 is HW off, 2 is CH off and 3 HW on and 4 CH on...(so far so good). Each time the programmer fails, the effect is no CH unless HW is selected. Take the programmer off the wall plate and put it back on and it works for a few days. The wall plate has been changed as well as it was a suspected bad connection on the programmer connection pins. Fit a brand new programmer and all is well for say a month and then the same symptoms start again.

Although changing the programmer clears the fault for say a few weeks, so does taking the original off the wall plate and putting it back on....that works for a while.

Boiler fine, plenty hot water and great heat from radiators. Just when working as a twin channel this odd effect occurs. Motorised valves operating correctly and BG has changed the valve heads three times and replaced the room stat but can't pin the fault down. Back plane links set for independent, 24 hr prog and pumped system.Wiring on SM1 wallplate all ok and connections solid.

This is annoying, as when this happens the only way to get the boiler to fire up and provide the CH is to switch the HW on or I suppose would have to have the HW and CH to set to exactly the same times and lose the independent control which is not clever.

My theory so far is that the programmer is a pretty poor fit with the wallplate and the pins on the programmer seem to lose contact with the wallplate from time to time and the very act of taking the unit off and refitting might be just getting an intermittent good low resistance connection......Totally baffled.

Exactly the same problem with mine same timer Drayton Control unit. I changed everything from motherboard to thermostat you name it I bought a 2nd new you control unit. Still experiencing the same problem. Today I put the old one back after resetting it central heating working again. I will look into finding a different timer control unit when I speak to a technician because this Drayton unit clearly does not what do the job properly.... The first control unit is several years old the second control unit is brand new. Yet putting the old unit back seems to of resolved the problem for how long only God knows. But I'm absolutely convinced that it's the Drayton control unit at fault.