CH not firing after rad bleed

D

Digitalboy0

Joined
8 Oct 2023
Messages
6
Reaction score
0
Country
United Kingdom
Right so this is a long one so do bare with me !
Im not gas safe but i am a multiskilled engineer so have rough knowledge when it comes to heating and plumbing etc.
So my radiator brackets was coming off my wall so today i valved off the rad and removed it from the wall and refixed the brackets and fitted the rad back
All was going ok and i went around the ground floor bleeding my radiators incase any air was put into the system.
Until i got to the kitchen radiator to which my suprise the bleed screw was that tight it snapped and i ended up with my whole CH water on the floor.
So i repaired the leak and filled my system back up from my top floor (btw i have a 3 story house with 3 thermostats one on each floor my boiler is a
logic heat 15 which i believe is a heat only open vent boiler).
Now my hot water is calling for my boiler and firing fine however my CH now is either not calling at all and my pump not working or it calls on the boiler but we never get a FIRE light to say its lit.
I do believe iv prob got a air lock in the boiler as i believe these boilers have a padel sensor for water flow and that might be my issue but im draining and draining my rads and not getting any air out and cant seam to find a drain on the boiler apart from a heat exchanger drain that i would rather not touch unless i have to,

can anyone help out ???
 
Did you open any 2/3 port valves when refilling? What is your pressure gauge reading?
 
I didn’t open any valves when I filled no system was off ! However I have found more info out now that if I run the HW and the CH at the same time the heating is working as it should however just running CH on its own I get the call symbol on the boiler however I don’t get the fire light to say it’s lit …… this is odd
 
Could be coincidence that your motorised valve had failed. Try powering down at the spur for about 10 minutes and then turn back on and try again
 
How many pumps do you have on the system ? What controls do you have ,stats, programmer/ timer ,and motorised valves ?
 
Tried powering down for 10 and starting again and nothing .......
So iv got honeywell valves
Wilo Pump
Horstmann centraurplus c27 programmer

UPDATE #############
So if i run the CH the pump starts up and the motorised valve opens and you can clearly hear and feel the water pumping around the system
the boiler is a C symbol on the screen that means RUN however the burner light never comes on and we have no ignition.
So to me everything is working as intended however the burner is not lighting and i cant figure out why .......

If i run the HW again the motorised valve opens the pump starts up and the boiler gets a run symbol and fires up as it should all happy .....
This boiler is a heat only so not combi or anything so same water does the central heating and the hot water so please someone tell me how this can be as my head is hurting from scratching

Thanks
 
Do all radiators heat fully when programmer is calling for domestic hot water and central heating together ?
 
Yes all of ground floor did apart from the one furthest from boiler was a lot cooler …..
 
Yes as long as the hot water is on the heating works fine however hot water off the heating will only make the boiler turn on it won’t make the boiler fire up
 
When you run CH only you say the pump starts and then the motorised valve opens- is that what you mean? Do you have 2 or more 2 port valves or a 3 port valve? Is there a wiring centre somewhere - if yes, have you investigated it? (some are just terminal block, some are full of relays).
EDIT The C on 'the screen'- is that on the controller display or the boiler display? Do you have access to a multimeter, are you comfortable with using it on 240v systems?
 
Yea when I run CH the pump starts as normal and the motorised 2 port valve opens “I have 4 of these 3 for the central heating one for each floor of my house and one for the hot water” there is a termination block on the side of my hot water cylinder yes. The C is displayed on the boiler and this means it’s being Called for and should be followed by a blue ignition light to say the boiler has lit and it’s getting hot however this blue light doesn’t come on however it does if I run the hot water …… it’s the same water that does CH and HW so this is confusing why it’s not lighting on the CH but will on the HW yes I’m fine testing the 240 side as I am a electrical engineer
 
If your Wilo pump displays the power in watts, W, note the readings on HW only, CH only and CH+HW, its possible that the boiler is monitoring the rise in pump head when it starts and isn't seeing this on CH only.
 
You must log in or register to reply here.
Back
Top