Fault with Drayton Lifestyle Programmer

[blackbirdxx]

Hi,

I have an S plan central heating system with the 2 valves operated by a Drayton Lifestyle LP822 programmer. The CH works fine but the HW has an annoying intermittent problem and only works for about 50% of the time, despite the green lights coming on as they should. I have replaced the programmer head and the HW works absolutely fine for about a month and then the original problem returns. If I remove the head and refit it, it works fine for about a week and then the problem returns. It's as if when you switch the power off, the unit reboots itself and works as it should for a while.

I have looked on the internet and find a number of people have experienced very similar problems with Drayton programmers. Unfortunately, I have been unable to find out exactly what the problem is and how it can be fixed. Simply buying another head doesn't fix the problem.

Any ideas or experience of these programmers will be much appreciated....

 

[ericmark]

There are three items which can stop the show heating programmer thermostat and motorised valve. From what you say I would be looking at thermostat. However better to test rather than guess.

There is normally so indecation on valve even if just bleed leaver goes slack.

 

[blackbirdxx]

Hi,
Should have said, but both the cylinder thermostat and HW zone valve have been checked as good when the HW refused to power up. Everything is wired up correctly and the programmer was identified as the culprit.

 

[oldbuffer]

Sounds like a poor connection between programmer and wiring back plate. Presumably when you bought the new programmer it came with a new back plate. If you are confident working with mains electricity and have the necessary tools, why not change the old back plate for the new one. Shouldn't cost anything and one more possibility out of the way.

 

[ianmcd]

As @oldbuffer says put the new backplate on, the selling point was that they were interchangeable but they are really cheap items and the contacts become worn and splayed

 

[blackbirdxx]

Sounds plausible but why does the unit work for a week or so after taking off and refitting the programmer from the backplate? It maybe due to the fact I'm switching the power off and on again and rebooting it somehow. Is there something inside the programmer which fails or resets on rebooting?

 

[Alec_t]

Another possible culprit would be a programmer relay contact not making a good connection. The relay contacts are rated "2(1)A 230V a.c. each switch", which isn't generous if they switch a significant load. It's also possible that the relay coil energisation is marginal, so any power dip could result in failure of the relay to pick up.

 

[blackbirdxx]

I tend to agree with you. What confuses me though is the unit works every morning 100% but doesn't come on in the evening like it should despite timings being correct. Also, the system is only 1 year old so you wouldn't think the contacts would be worn. Rebooting seems to cure the problem albeit temporarily.

 

[blackbirdxx]

Noticed that the plumber has left the securing screws to the underside of the programmer loose. Presumably because it sits above the junction box and you can't really get a screw driver in to tighten them up. Would leaving the programmer face loose on the backplate cause the problem over time?

 

[stem]

The programmer isn't the only switch in the hot water control circuit, there is also the hot water cylinder thermostat.

However, there's a fairly easy test that can be done. You say that the central heating works OK, so I would move the hot water ON wire from terminal 3 and put it in terminal 4 with the central heating ON wire.

During the test, it will mean that the hot water will switch 'on' and 'off' according to the central heating timings, but you will know that if then the hot water works OK, the problem is with the programmer or its backplate. In which case as a programmer will come with a new backplate replace them both. If the fault with the hot water continues, the fault is elsewhere.

 

[blackbirdxx]

Hi, thanks for this. Someone else had suggested this test in an earlier post I made. This time however, its def something with the programmer for the reasons I discussed in my posts above.

 

[blackbirdxx]

Hi,

This post below explains my problem to a tee except my prob is with the HW rather than the CH.....

Has anyone experienced this?

https://www.electriciansforums.net/threads/strange-fault-with-drayton-programmer.55870/

 

[blackbirdxx]

Next stage I'm guessing is to buy a new programmer and replace the back plate as well. Wickes are selling the units for £52 which seems OK.

Unless someone can suggest something else of course?

 

[ianmcd]

you would have got a new backplate with what you call a head you cant buy them seperate