drayton lp722/ BGas up2 timer problem

[ahearsum]

Hi

I've had 2 British Gas UP2 and two Drayton LP722 timers in the past month all exhibiting the same fault; CH set to boost for one hour after the last off-time of the evening will often (not always) result in the CH being on all night. In the morning the letters BST are still visible on the timer.

Background: British Gas installed boiler 2 years ago. Nothing but trouble. In the past 2 months: boiler, pump, divertor valve, tank stat, room stat, wiring and timer all changed. In other words a completely new system. And yet the timer problem still persists. Logically it must be the timer as the UP2 and LP722 are essentially the same and the previous timer, prior to all this trouble, worked fine.

Any thoughts?

Thanks

 

[stoker122]

Isn't the boost button on this an advance? If it is, the advance is telling the programmer to stay on until its next off time.

 

[dancinplumba]

Isn't the boost button on this an advance? If it is, the advance is telling the programmer to stay on until its next off time.

no its a 1 hr boost like op says

 

[mfgs]

Isn't the boost button on this an advance? If it is, the advance is telling the programmer to stay on until its next off time.

I think these have a boost and an advance. Why do you boost for an hour after the off time? Why not just set the off time for an hour later if you are doing it all the time? Is it only the boost that is keeping the heating on?

 

[stoker122]

Have all the other components been changed due to the same fault?

 

[ahearsum]

I'll reply to all of the above:

It has an advance and a boost function.

I don't boost all the time and in any case I want the flexibility if I stay up late on a friday night watching crap on the television just to boost until I go to bed.

The components were changed one by one to answer the problem of the boiler broadly only firing for 10min then off for 40min, on 10 off 40 and so on......... The boiler was the second last thing to be changed then the tank thermostat. The boiler problem was fixed but then the timer problem manifested itself with the first british gas UP2 timer, then a second then I got it rewired, the timer problem persisted, I got a Drayon LP722, problem persisted, I got a replacement LP722, problem persisted.

I'm perplexed. Logically the timer is at fault. I'm thinking if i get another brand compatible with the Drayton backplate I can eliminate, or not, the timer as the source of the problem. Its getting expensive though.

Have all the other components been changed due to the same fault?

 

[TBServices]

"Logically" speaking, it's highly unlikely you would have that many timers creating the same fault.

What boiler do you have?

 

[ahearsum]

"Logically" speaking, it's highly unlikely you would have that many timers creating the same fault.

What boiler do you have?

Yes, I suppose so. I was thinking along the lines of it being a design fault also considering that everything has been changed
boiler? It's BG branded Gloworm condensing boiler. 330+ I think

 

[SimonG]

I would be looking at a sticking divertor for my first port of call. I know you say you have had it changed but things that are new out of the box sometimes don't work.

 

[ahearsum]

I would be looking at a sticking divertor for my first port of call. I know you say you have had it changed but things that are new out of the box sometimes don't work.

Thanks but the divertor valve moves to the correct positions when only CH, only HW and both are on ie left, right and in the middle. There doesn't seem to be any physical impediment.
Would a sticky divertor valve result in the boost symbol (bst) being present on the timer display after the requested hour was up?

 

[stoker122]

Hi

In the morning the letters BST are still visible on the timer.

Thanks

Is it possible BG have sorted one fault and now coincidentally you have another fault?

 

[ahearsum]

Is it possible BG have sorted one fault and now coincidentally you have another fault?

Entirely possible. But its difficult to believe that all four timers have the same problem other than because of a design fault. Additionally could any of the components that the timer is controlling, feedback to the timer in such a way as to cause it to display the boost symbol? Isn't the boost being on or off entirely dependent on the timer settings?

 

[stoker122]

You would need to press boost to activate it.
Was the original UP2 fitted and working for two years without faults?

 

[ahearsum]

You would need to press boost to activate it.
Was the original UP2 fitted and working for two years without faults?

No I had a different timer that worked absolutely fine. British Gas changed the timer to a UP2 in an effort to fix the original malfunctioning boiler problem. So the waters are a little muddied in that when the timer was changed to a UP2 there was a much bigger problem with the boiler so my attention wasn't on the timer alone. That first up2 and subsequent up2 and LP722s certainly all have/had the same problem.

 

[stoker122]

I would be very surprised if all four of what are basically the same programmer had the same inherant fault (but it is possible).
Have the BG guys checked the wiring to the back plate at all or just changed the programmer. Also have they changed the backplate?
I am wondering if a poor connection between the backplate and programmer could be causing the problem.

 

[ahearsum]

I would be very surprised if all four of what are basically the same programmer had the same inherant fault (but it is possible).
Have the BG guys checked the wiring to the back plate at all or just changed the programmer. Also have they changed the backplate?
I am wondering if a poor connection between the backplate and programmer could be causing the problem.

Thanks for your time and suggestions. I might get BG back again although our relationship is a little strained after the 2 year boiler saga. I may alternatively change the timer brand. Any recommendations on a good replacement?

 

[stoker122]

I use would use a Honeywell (ST94000C) I have never had any problems with them.
Good luck!:smile:

 

[ahearsum]

I use would use a Honeywell (ST94000C) I have never had any problems with them.
Good luck!:smile:

Thanks

 

[TBServices]

I use would use a Honeywell (ST94000C) I have never had any problems with them.
Good luck!:smile:

I agree, but the wiring/components in the system need to be checked.

 

[skipdy]

The LP722 has a combined advance/boost button. Pressing the button once will advance the unit to the next time period, if you then hold the button down it will initiate the boost feature but only after the advance time period has elapsed, this would result in the BST still being shown in the morning and consequently the heating being on all night.

When selecting boost only make sure that you only have BST on the screen and not BST ADV