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Doesn't look like the vallient engineer has resolved the prob from the last post it still sounds like the boiler is constantly on to me that can only point to the live link being left in

Is the programmer opening and closing the zone valves ?

Valiant engineer probably wouldn't have noticed! Had older one with f78 code - air bubble in pressure sensor... Valiant have a kit which lifts sensor up 5 mm custard paid for 3 parts service thing..... Got a pump expansion and something else!
 
I think the problem is that the installer has left the 24v rs link in the boiler
This needs to be taken out when using external controls hense why the boiler is on constantly on
the reason it keeps going on and off all the time is that the boiler is just pumping round a small circuit when the zone valves are shut then when it reaches 75 degrees will turn off eventually the boiler will overheat and u will have to keep re setting it
When the zone valves are open ie when on at the proggramer the boiler will work fine
Should be a simple fix really hope I explained this ok

Thanks Phil, when in auto mode the zone valves open and close as per the time no issues.
today the engineer from vaillant came around again, he said the thermostat temperature was more than the flow temperature in the boiler hence it was repeatedly turning on and off, then he changed the temperature in the boiler to 70 and set the thermostat temperature to 65 and said it should be fine now and left. He also reduced the load to 24KW from 36KW.
After these changes the boiler was on for 25 mins at one stretch to heat up the water in the cylinder after that it's starting once every 15 mins for 3 mins and shutting off. when it starts the burner comes on for 2-3 mins then the extractor fan with runs for 8 mins this continues so there is constant noise either burner or fan 🙁 will check with the installer if he has removed the 24v rs link as you suggested.

Regards,
 
.........yes

20131001_165200.jpg

I can see the 24v pin is removed, is that what you guys were referring ?

Thanks,
 
There is a black going into RT.
Check external wiring and zone valves for sticking micro's

My thought is there maybe a perminet live in RT as it's a new installation it needs checking by a competent person really
think this person is doing the work himself as croppie said be carefull
 
Guys,
I am not doing the work myself, the issue is because my builder has used a useless guy for installation and its been a struggle with him to get some one to fix it 🙁

20131002_072128.jpg

20131002_072033.jpg
 
Last edited by a moderator:
Get somebody in ASAP to sort this mess out can't really help u out anymore than that my friend
 

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