New rad, Central Heating is OK, No Hot Water

[Alancable]

Hi all, new to the site.
I've searched previous forum posts but can't find the answer to this one -

I recently fitted a new Rad in my bathroom by isolating the previous one by closing valves either side. After a couple of attempts to cure leaks all was fine so filled the rad with water and bled the air from it. Since then, my HW cylinder will not supply hot water to the taps. The inlet pipe to the cylinder is cold even when CH system is on (red hot!) and pump is working fine. I've bled the other rads several times and all of them are air free, also tried bleeding the pump but all ok there.

I may have made the error of opening both valves on the new rad before bleeding so may have forced air round the system?

Is it still an air lock problem?

My system is gravity fed.

HELP !!!!!!!!

Forgot to mention - HW is gravity but Central heating / cylinder coil / Heat Exchanger is pumped.
I'm such an ameteur, it's embarrassing !!!

 

[WHPES]

Is there a bleed point at the top of the cylinder coil? Probably full of air and wants letting out.

 

[Alancable]

Thanks for your reply WHPES.

No bleed point that i can see. the top coil pipe has another pipe branching off and goes up into the ceiling and I think to a smaller water tank (expansion) in the loft. If no bleed valve then how can I suck the air through to clear the air ?

 

[WHPES]

Is there any water in the F&E tank? If so, can it get into the circuit (no blockages where it enters)?

 

[Alancable]

F&E ? If that is the smaller tank in the loft then yes, there is a small amount, about 1/4 full. Not sure on any blockages will have to take a look. Maybe the water level is too low? Should it be full ?
Sorry to sound so clueless, I'm only a budding DIY'er !!

 

[stevetheplumber]

its probably an air lock in the cylinder coil you need to loosen the top coil connection to release the air in the coil

 

[Alancable]

Thanks for the advice guys. Will try those suggestions. There is water coming out of the hot taps but is cold. I guess due to the airlock the hot water in the system is not circulating properly.

Thanks again for all the advice which has provided the answer -

The ball valve in the Header (F&E) tank was stuck so the water level was very low. Once I unstuck it and the tank filled, hot water was restored the the cylinder coil.

I'm sure it is usually one of the things that get checked first, but had me foxed for a bit !!

 

[moony]

had this problem the other day - first thing i do is give the ball a wobble after system is drained....

vent your rads again too as there might not of been enough pressure on the system to push air out last time you did it.