Modena 80e CH problems

[yorkshirepud82]

Hi Folks

i hope you can offer some tips you appear to be a very knowledgeable bunch i have had a look around for suggestions for my problem or a solution but have not found one so far so if it is a repost my apologies

as the title suggests i have a modena 80e boiler in my house, the boiler was in ther when i bought the property in 2005 and in this time period has only ever had one issue that really wasnt the boilers fault. there was an issue with the origional thermostat in the hallway which broke and so the boiler didnt know what the temperature was. since i was in a bind and have no plumbing or central heating knowledge i got BG to come out and the fella they send replaced the thermostat with a new one ( a bg branded one) and since that time everything has worked very well.

until yesterday when it was a little cool in our house and i decided to fire up the central heating. the boiler was at that point within an 'on' period on the timer but was not currently running, what i would normally do is go into the hallway turn the thermostat anticlockwise to below say 17c where it would click and then turn it back where it would again click i would then leave it at 21c and the boiler would fire up after that time. it was after a while i noticed it hadnt so i checked the panel

pressure is fine 1br
no other warning lights are on

the boiler fires up for DHW fine but just refuse to come on for CH, i tried any way i could think to start it, i changed the settings to constant CH, i reset the boiler with the reset switch and i even turned it off at the mains no joy

my un-educated guess is that something has again gone wrong with the thermostat or some other control along the way. you'll have to excuse me if i made some obvious amateur mistakes but im really not that clever when it comes to boilers, what can i say my dad is an ex coal miner and the boiler i was brought up with was coal fired

hope you can help

 

[bengasman]

How long has the new roomstat been there?

 

[yorkshirepud82]

Definatly more than 18 months. it seems to be physically ok, i couldnt get the cover off to check but its not been knocked or bashed

 

[kevplumb]

deffo sounds like an external control fault

 

[yorkshirepud82]

despite being clueless at central heating its what im thinking

i quickly scanned the manual yesterday and it suggested disconnecting some terminals to the clock to bypass the external thermostat. im a bit apprehensive about anything like that to be honest

 

[kevplumb]

remove wires from terminals 3&4 AFTER you switch the power off

and link them together the terminals that is

that cuts out all the external controls

if your not sure time to start phoning

 

[yorkshirepud82]

i think it might just have to come to that kevplumb

computers i can handle this stuff is witchcraft i might as well sign up to some CH cover and get them to fix it.

i still appreciate any suggestions though folks you have been most helpful so far

good thing im fat and its not winter

 

[yorkshirepud82]

i've just had an idea would it be worth say replacing the thermostat with a digital one and if that doesnt fix it get someone to look into the sytem? i have a friend who is a spark and should be able to swap over a thermostat

 

[kevplumb]

ask him to have a look first

always worth a try