DRAYTON Lifestyle LP112 Programmer (Faulty?)

[reluctanthandyman1]

Anyone out there who is good with wiring faults on a central heating system? Can you make an educated guess on this please?

Is it possible that my Drayton Lifestyle Programmer could be possibly "interfering" with the proper and effective working of my cylinder stat if the wiring is wrong/faulty?

I have an intermittent fault which is causing me much confusion. I will be as brief as I can in describing it - When my 3-port valve is in Mid-Position is the only time when this intermittent fault occurs.

What happens is the boiler continues to fire even though the cylinder stat has reached its required temperature. It is as though the cylinder stat is being ignored by the 3-port and continues to heat the water up to the boiler stat's temperature. In laymans terms it is as if the cylinder stat is being "bullied out of the picture". And the 3-port remains stubbornly in Mid-Position when it happens (not seized or jammed there, but being held there electrically).

Both the 3-port and the cylinder stat have been renewed within the past 2 months and have been tested as being in proper working order within the past three weeks - as I say , this is an intermittent fault which suggests some kind of electrical "glitch".

The question is - what is the most likely cause of this in terms of a faulty wiring scenario? What is it that is at fault which causes this problem only on an intermittent (about once a day) basis?

 

[reluctanthandyman1]

Could it be the Programmer? And if so, in what way? I ask this because , as stated above, the 3-port and the cylinder stat are both brand new and have been recently positively tested.

 

[D_Hailsham]

Read How a mid-position valve works; it will save me having to spell out how to diagnose the fault in your system by a long question and answer session.

 

[Agile]

Both the 3-port and the cylinder stat have been renewed within the past 2 months and have been tested as being in proper working order within the past three weeks - as I say , this is an intermittent fault which suggests some kind of electrical "glitch".

I suspect that is the root of the problem.

Why were they replaced?

Who replaced them?

Did they check the wiring was correct or just try to put the new ones in the same way as the old ones?

How many active wires to the cyl thermostat?

 

[reluctanthandyman1]

Thank you both, gentlemen.

The 3-port and cylinder stat were both replaced as stated by a supervising heating engineer from the firm with whom I have a Central Heating insurance cover policy. I have a feeling that it was simply easier for him to replace these components rather than carry out a full diagnostic testing of the circuitry connecting them with a multimeter - the only component which hasn't as yet been changed is the programmer. He stated that it would be a long procedure to carry out a full testing of the wiring as most of the wiring into my terminal centre in the airing cupboard is wired into it from "behind". I must say I was somewhat sceptical of this response. He also said that if the problem was a wiring problem then it probably wouldn't be intermittent - it would be constant.

Surely testing the wiring and electrical connections isn't that difficult for someone who knows what they are doing.

The frustrating thing is - when he replaced the cylinder stat the problem went away for a 2 full weeks before making a re-appearance last night.

Can you explain therefore why this problem is an intermittent one
and what is the most likely cause of it?
Can the programmer be an influence on it?
I must say that it is confusing the hell out of me.

It only happens when the 3-port is in mid-position.

 

[reluctanthandyman1]

I think there are 3 active wires to the cylinder stat.

 

[reluctanthandyman1]

And this new Cylinder Stat was installed simply by removing the wires connected to the old one and connecting them to the new one - no access was gained into the wiring centre to make sure that the "other end" of the cable was in proper order.

 

[Agile]

Different makes of cyl stats have different terminal positions and numbers as well!

Its not necessary to access the wiring center.

Many dont really know how to correctly connect them!

I do it according to the NC and NO connections as thats the only constant information on different units and what relates to the electrical operation.

Some will say that they can check it quickly but to do it correctly I always find takes quite a long time like 30 min plus.

The problem is one cannot assume they are wired according to the standard method(s).

The other is that in many cases wires disappear into the wall or floor and is difficult to check when parts are in another room.

Tony

 

[reluctanthandyman1]

I've got this same engineer calling back again on Thursday morning to this time carry out a full wiring and component check to see if the problem can be traced to its source, and I can have my central heating system back again in proper working order.

Would I be right in saying that the source of the problem can be definitely found if he carries out a full check with a multi meter?

The only reason I query the possibility of a programmer fault being the culprit is that I recall replacing the Drayton LP112 programmer (like for like) 4 years ago to deal with a problem whereby my HW wasn't "activating" at all until the CH cycle had finished its first cycle, which meant that the water was cold/lukewarm early in the morning. It was only when the CH has finished its first cycle that the HW then kicked in and activated. After replacing the programmer with an identical new one the problem was rectified (and that was again after the 3-port and the cylinder stat had been renewed!).

So - can the cylinder stat be rendered "impotent" by a faulty Programmer and if so, how?

And, once again, can anyone explain in a general sense the reason for a wiring fault being intermittent rather than constant in this particular context?

 

[D_Hailsham]

When my 3-port valve is in Mid-Position is the only time when this intermittent fault occurs.

How do you know the valve is in mid position? Are all three pipes equally hot?

If the valve is in mid-position it should go to CH only when HW goes off.

What happens is the boiler continues to fire even though the cylinder stat has reached its required temperature.

While you are waiting for the engineer, here are a few simple tests you can carry out when the fault occurs.

1. Turn cylinder stat down to minimum. Does the valve go to CH? If it doesn't:

2. Turn cylinder stat up to maximum. Does the valve go to CH? If it doesn't:

3. Turn HW OFF at programmer. Does the valve go to CH?

What is the make and model no of your 3-port valve?

 

[reluctanthandyman1]

Hello again DH. Sorry for the delay in replying but I thought I would wait until the engineer had been to do his stuff and see if this problem would now be sorted. I wanted to keep a close eye on the behaviour of my system over a period of time to make sure all was right (sad I know).

Unfortunately the problem has made a re-appearance after everything working perfectly well for 9 days after his visit.

(In answer to your questions - the 3-port valve is a Drayton MA1 and the indicator lever on the side of it gives a clear view as to what position the valve is in when the problem occurs - it always occurs when the valve is in mid-position.)

I was at home yesterday evening when the problem yet again occurred (the second time since the engineer's visit). This is the sequence of events.....

The heating had recently come "on" as per its programmer timing to do so, and the boiler was firing to heat it - the 3-port was at the CH position.
I then went to wash my hands, after which the HW "called" for heat. The 3-port moved, quite correctly, to the mid-position.
However, it then remained steadfastly in mid-postion - beyond the temperature point at which the cylinder stat had been set (water temperature extremely hot being the telltale sign).

I then turned the Room-stat right down ("click" clearly heard) and returned to look at the 3-port indicator lever - it remained on mid-postion.

I then turned the cylinder stat right UP to maximum, and the 3-port then moved across to the HW postion, after which I then reset the cylinder stat to its usual 60 degree temperature.
I then went back to the Room-stat and turned it back up again, and the 3-port then went, as it should, to the CH position. Everything then worked as it normally should for the remainder of the evening.

It was as if the cylinder stat had somehow "fallen asleep" and needed to be manually "woken up" to do its job.

Given that the engineer and his multi-meter has been and checked the wiring between the 3-port and the room-stat and the cylinder stat and the programmer (and no issues found) - and given that the cylinder stat and the 3-port are both newly replaced I wonder if you, or anyone else out there, can provide any answers to these questions....

1. Is it possible that the Room-stat can be causing the problem and if so, how? (The current one is an electronic Drayton model with a simple dial on it to set the temperature, which I normally set at 20).

2. Is it possible that the Programmer could be be causing the problem and if so, how? (This is a Drayton Lifestyle LP112).

(It is worth mentioning that the issue of the cylinder stat seeming to "fall asleep" as previously mentioned occurred 4 years ago with my system and it was only when I changed the Programmer (Drayton LP112 like for like) that the problem resolved itself - and that was after cylinder stat and 3-port were renewed.
I would just like to know HOW that changing of the Programmer resolved the problem back then - in what way could the Programmer have caused the problem?).

 

[reluctanthandyman1]

Could the "internal wiring" within the Programmer body itself rather than the "external" connections which hook it up to the other components on the system be causing the issue - and once again, if so HOW?