Head Scratcher...

[CES]

Ok, Im a bit bamboozled with this one

Little old lady has a WB Greenstar 24i Junior fitted with a MT10RF Programmer & Stat. It was fitted by BG a few years ago and Ive been out to it twice now with an intermittant fault.

She turns the stat down to 5 at night so that it doesn't burn gas unnecessarily and occasionally the boiler fires up during the night and the rads get hot (according to her). The temperature has never been down low enough to kick in the frost function. I checked the programmer and everything seems to be in order, changed the batteries, made sure the ECO light was on to prevent preheat.
It lasted for about 3 weeks and its now doing the same thing..
Im considering changing the programmer as thats all that I can see that would be doing this?
Anyone got any ideas or came across this before?

 

[Ivor Bates]

My 30CDi comes on around 2am every morning, circulates for a minute then shuts down, nothing to do with the room thermostat at all. And the temperature has not been cold enough either. But without fail it will turn on every night around the same time, might be a dodgy frost stat, but most people are in bed at this time of the morning so would have no idea whether the boiler is coming on or not...spooky

 

[nysk2008]

R u sure its not the pre-heat? hold the eco button until its lights up green - green light ON = pre heat OFF

 

[CES]

Definately, I made sure to tell her that the green light has to be on.

 

[stevetheplumber]

id check this boiler doesnt have a pump exercise program some now come on for one min every 24 hours

 

[Barry98]

id check this boiler doesnt have a pump exercise program some now come on for one min every 24 hours

isnt that just on newer ones ?

 

[GasmanxxxR1]

Contact worcester they might be able to help

Is the room stat accurate or does it think it is colder than it is. Check it with a thermometer

 

[bert large]

I've got the old standard efficiency Worcester 28i Junior & that has definately does a pump spin every 24hrs so would have thought the newer ones do too.

Meant to add that the pump spin program shouldn't cause the boiler to fire up though

 

[steve.d]

this boiler is is defo fitted with an "anti pump seizure" which runs the pump for 30/60 secs in a 24hr period

 

[armourer]

I would say she is hearing the pump spin up on the anti seize but the rads are not getting warm.
(confused customer maybe)?

 

[cdodds2004]

yea they defo have a pump spin i think its every 23hours 59mins or summit stupid like that! i would double check whats hapening im pritty sure she must be mistaking this,

is she using comfort or economy on the programmer? i tend to ignore the economy side, but maybe she is switching to the other stat or something?