cant refil my central heating. i suspect a blocked cold feed

[Buildaman]

the pump seems to be spinning freely but it is hot. am gradually getting 2 rads hot then switching them off till the next 2 heat but still no hot water?

thanks for the help

 

[JohnD]

when you've got all the rads hot, and turned them off, I expect you will get flow through the cylinder.

Did you alter any of the lockshield valves on the rads?

are you getting any gurgling air?

Is the pump hotter than the pipes beside it?

 

[Buildaman]

i have chased the hot rads to the last one and turned them off got them all going do i swith off at the trv or do i need to turn off the lockshield too? if i do start to get hot water in the cylinder what shall i do next. am off up to check the hotiness off the pump

thanks again

 

[JohnD]

It will be sufficient to turn them off at the TRV

You have now proved that there is flow to all the rads.

It is possible that there was air or something obstructing the flow, but more likely, you had some rads that were so wide open that all the flow went through them, and that was the easiest route for the water to take, so nothing went through the others. This can be corrected by Balancing the radiators. The lockshield need only be opened half a turn or so to let the rad get hot, and this will restrict flow so there is enough to be shared round the others and the cylinder.

Have you recently altered the lockshields?

 

[Buildaman]

no i havent so no idea why this has happened. success on the heatingh but still no hot water pump is running ok when the cylinder stat is turned from 0 degrees to 70 i can here the pump kick in but cylinder does not heat up. it heats when i use the immersion side.

any ideas gratefully accepted

thanks

 

[warmadmax]

i cant refill my central heating after draining the system. everything is in the loft but i cant be sure as to which is the cold feed. i have pics but no idea how to attach any ideas?
[/img] View media item 51221 View media item 51222

in the first picture, under the pump there appears to be a 3 way zone without the actuator attached (the "t" junction with a spindle sticking out)

hot water will never get hot if the valve isn't in the mid or HW position.

 

[Buildaman]

i put it in the mid position. i took off the head as i didnt think it was working and that it might be stuck. ihav had that whole 3 port valve apart and does turn freely

thanks

 

[warmadmax]

the actuator head contains the springs and motor to keep it in the mid position,

so what's probably happened is you've taken the resistance off the valve and the pump's pushed the valve one way or the other (in this case CH only).

you'll want to re-instate the head for proper operation anyway,
if you come to do this again, there should be a lever on the head to move the valve manually.

if it's not working, replace it as it will divert the hot flow to where it's being called for rather than sharing it out willy nilly,
come summer you'll have hot radiators when you don't want them to be!

 

[Buildaman]

i took it off as it seemed to be not working correctly
i undone the compression fittings and took out the valve itself to make sure it was running freely and put it back and took that photo i manually turned the spigot part to midway as it is in the photo but still no hot water. the head is now back on but still to no avail

 

[Weedrip]

given the cylinder is laid on its side could the coil be partially air locked?

is there an air bleed valve hidden under the lagging on the cylinder flow?

 

[Buildaman]

there is a very high level air bleed valve that i bled and indeed air rushed out and this was on the cylinder flow

but i had still no hot water

 

[Weedrip]

That being the case its probably more air in there, the HE is a coil (loops within the cylinder) it will need the full flow from the pump to probably shift it all and you may have to re-vent in stages.

first off however you need to set the 3port valve to feed hot water cylinder only to get the full flow of the pump round the coil and hopefully drive any air within to the vent point. (worth checking the pump is set to max)

good luck

 

[Buildaman]

oh excellent i will try that in the morning thanks for that

come so far in a day would be nice to sort it

 

[Buildaman]

i have hot water guys many thanks think my system needs balancing as not all rads heating quite right but its so much better

thanks thanks thanks

 

[Buildaman]

it turns out that the pump was knackered probably due to the build up of crap. new one fitted and heating working like a dream