I have a Worcester Bosch Greenstar 12 (installed 2011) with…

Hi mike, as in my question, i have already done this numerous times.

it does not reset. the issue is without pressing button 2 the green light comes on anyway. if i turn down the dial on the right, the green light goes out, and i press button 2 to manual override but the green light does not come on.

yup. i have the instruction from drayton on commissioning the digistat.

yes everything was working fine before i changed the batteries. no leak. it was weak and the thermostat showed empty battery (sign to replace). yes the power switch has an in line fuse.

mike i don't think you are speaking about the same system. the batteries i refer to are in the room thermostat. the scr is powered by mains

thanks mike for trying.

hmnn... i had already left the batteries out of the room thermostat. i too think it's something relatively simple but don't know where the fault is. on the scr digistat, the alarm (red) light is permanently on.

also, the boiler seems to be off (no green light). however the radiators have come on.

sorry i don't have better news, tried partway. still stuck on same spot.

batteries out of remote thermometer.

i switched off power to receiver.

when i swtch on power to receiver, the alarm light remains a constant red.

the boiler comes on and the green light comes on without me pressing button 2.

if i wait 1 min, the green light goes out by itself. then i press button 2 to overide but the green light doesn't come on.

so is it that the system is not responding to the digistat?

not cold. 59 F/ 15 Celcius. nothing frozen.

not sure how to check the system pressure but none of the pipes are leaking. yup they are copper.

mike i'm stuck. i dont know what i'm looking at. there's the greenstar downstairs and then there something that resembles the tank in the picture you sent me in a cupboard upstairs with a snake pit of pipes coming off it. i am unable to identify a valve switch. no leaks as far as i can see.

i have tried the yelling believe me. i have also had the system off for a few days. and tried recommissioning. hence knowing the whole which button to push by heart. as this system has only been installed 2 years ago i find it unbelievable that it would need to be replaced when the previous boiler worked for more than 10 years.

can you think if there is a switch somewhere that maybe stuck? in the receiver maybe?

ok i've done that. the only change is the alarm button is now gone.

Duracell AAA batteries in the remote thermostat

Sorry you are right. they are AA 1.5v which is what i had replaced the originals with. after the last place transmitter under the boiler and leaving it as such overnight, the red light of alarm on digistat has disappeared and the boiler has not come on since.

hey mike... sorry this seem to be long drawn out.

the thermostat comes on with the new batteries. however, the boiler still continues to go according to its own timing which doesn't follow the set timer.

i have just reprogrammed the timer and going to see if this makes any difference.

makes it harder to monitor as i'll be back at work. (am trying to sort this out while at home nursing a flu)

hmmn.... i will check out how it responds to the new timings. maybe try to reset the whole system again one more time and if not, i might have to get someone physically here to start checking or indeed replacing. not so happy to hear that.

thanks mike. this virus strain is hardcore. good you getting your dose up.

it's like u my online buddy. i get the feeling you enjoy solving problems. thanks for being up for the challenge.

so no joy with the timer being reset. the heater definitely comes on and off on it's own without following the timed sequence.

the room thermostat and the digistat scr are talking cause when the temp drops below the 'set temp', room thermostat shows a flame on the display which should mean heater come on. digistat shows green light for timer override but boiler not on.

i spoke to drayton before coming here and they just said, sounds like a valve is sticking. get a technician.

:) seems like the other experts think i'm in good hands.

ok i'll be honest. i have no idea where this motorized valve is that i'm looking for. i'm not sure if the first pic is significant (this is prob water temp right?). 2nd pic - this is the pipes coming off the boiler in the cupboard.

and this is above the worcester unit.

ok maybe it's nerdy but i enjoyed that video. very educational. so heating is on, the timer is also on (could be coincidence) and the lever on the valve is floppy as the video suggests. switch mains off and the lever behaves as expected (some resistance and returns to the original position). as a total novice, would it be ok/advisable to start opening up the motor?

Ok so i've opened up the motorised valve and checked the gears (fine), the wiring is tight, nothing loose, the lever looks like it is depressing the microswitches (one more than the other, is this correct?)

took off the head and the bit behind it is pretty well greased. moved fine.

(btw, heating is on and hot water also is there)

so i recommissioned the heating again (try hey?) and so still stuck on the digistat not being able to manual override the worcester greenstar. (timer says boiler should be off). worcester continues to show green light for 5 minutes then goes out.

sorry about that. i had a blast at doing something for the first time thanks to you. (also managed to fix my printer today too although that one was reattaching a fiddly metal bit that seemed vital to the op). chuffed.

i'm beginning to think it could be digistat capacitor?

http://emalliab.wordpress.com/2013/03/06/drayton-scr-and-rf-2-fault-finding/

ok before the capacitor.... think i'm going to try this. something about the relay under the black cover.

http://www.fixya.com/support/t1204828-drayton_digistat_rf3_boiler

hmm... the black box is looking really difficult to get off without damaging the little catches. it is pretty obvious i've messed with it with all the scratches and busted catches.

not sure what a busted capacitor looks like. it looks fine from the outside. (looks like in this vid - http://www.youtube.com/watch?v=uQc0eyOKvwE) no leaks. i have no way of testing the circuit.

i am not able to overide using the digistat.

not sure how else you mean manual control. if using the worcester unit, i can turn the left dial from 'I' to 'O' and it will go off. and vice versa.

yup saw the bulging pic you sent. so this is what digitstat looks like.

relay lever looks ok? so am guessing it's the capacitor to be replaced

mate i like your style. nothing ventured by just throwing stuff away. this is the way to learn. but i'm beginning to think i'm near the end of my abilities. while there is a solder gun in the toolbox, i have not operated one b4.

no scorch marks as i can see. and unfortunately, no multimeter either to test. there is a bit of leakage around the metal rectangle. not sure what it is. the fuse? but no online panel refers to faults there.

back to the capacitor i think.

well now sir, i cant argue with that! grateful for your generosity.

ah... you might be on to something. i am only able to get the boiler to come on (green light above left dial) by raising the hot water temp.

not sure how to get the greenstar to kick start heating only as the system is not responding to the digistat.

have turned off HW at honeywell control panel.

no does not work. again, receiver overrides, green light comes on, clicks but boiler does not fire up.

so i think heating is on (raditor hot), the pump is running (sounds like a fan with water trickling). also the lever on the motorised valve is slack at the moment.

i haven't done anything different. the issue is that the boiler comes on and off on it's own seemingly.

it doesn't seem to respond to the RT or the override button on the digistat scr. (those two are in sync and appears working fine).

and so now the boiler unit is off again. (honeywell programmed timer has green light on for heating up, supposed to run for next 40mins).

yup you got it. it's come back on again. the radiators do get hot.

Hey Mike... hmmmnn... no changes. He was finding out more info but no solution yet. However I might have messed up the gear on the motorised valve by too much tinkering. now when the boiler green light is out, the gear was still in midway position and lever slack. and so the radiators remained hot. sighh.... i'm wondering if i got in a technician, would they fare better than us at fault finding or simply sugest parts replaced and see how it goes.

ok i will try to turn timer off tonight and see how that goes.

Andrew come back please??

no. even with timer off overnight the heating still comes on at whatever time the boiler seems to be firing to. any other ideas?

Sorry I haven't responded. Can you believe it? My broadband/tv/phone is down too. ok. i will go back to focus on the receiver. there is the digistat receiver. is there receiver in the boiler? could that be the issue?

I think after I rate you we may not be able to converse but want to say thank you so VERY much for your help in all this journey. You are a star!

ps: sorry it wasn't 'easy'.