Halstead Best 50, no hot water...

[Mike 123]

Have just installed a new cylinder but, after refilling,have found that the hot water doesn't get hot. Central heating works ok. When hot water is switched on, boiler fires for a few minutes then shuts down. There is no cylinder stat and I can't find any motorised valves
Any ideas gratefully received, thanks.

 

[Rob]

Sounds like an air lock in/around the cylinder coil. Is there way of venting this part of pipe work i.e the open vent or thumb vent ?

 

[Mike 123]

Will give it a go, but I did back fill the system (via the drain off- I was under the impression this would eliminate airlocks?)
Thanks

 

[Rob]

Will give it a go, but I did back fill the system (via the drain off- I was under the impression this would eliminate airlocks?)
Thanks

Unfortunatly not. Still needs appropriate vents in place.

rob

 

[Mike 123]

Is it just a matter of cutting in a tee with a vent on the flow? Pipework is 28mm and theres not a lot of room.
Thanks again.

 

[Rob]

If the cylinder is at a 'high' point on the system where you think are could get trapped then it 'should' have a vent.

You say there is not motorised valve is it pumped or gravity?

You could always try and losen one of the union nuts to the coil and it may drip but may also eventually clear the air??

 

[Mike 123]

If the cylinder is at a 'high' point on the system where you think are could get trapped then it 'should' have a vent.

You say there is not motorised valve is it pumped or gravity?

You could always try and losen one of the union nuts to the coil and it may drip but may also eventually clear the air??

House is 2 storey, boiler downstairs in kitchen, cylinder on first floor, f&e in loft. So don't think cylinder is at a high point.
System is pumped.
Will try loosening the unions first.

Original cylinder was 'opposite coil' and for a direct replacement I would have had to wait up to a week. Would this have anything to do with it?
Thanks

 

[Rob]

I dont know what that is

But turn rads off i.e by motorised valve or individually, increases pump pressure, then try the venting!

 

[Mike 123]

I think its when the flow and return are on opposite sides of the cylinder. Have fitted a cylinder with f&r on the same side, apart from the possibility of my pipework being iffy, would this have any effect?
Thanks.

 

[Rob]

Pretty obvious i suppose from the name . No it should make much difference as long as your pipework isnt doing any silly loops or anything!

Lets us know how you get on ..

rob

 

[Mike 123]

Will update you tomorrow.
Thanks v. much for the tips.

 

[ChrisR]

Vent at V

 

[Mike 123]

Problem sorted itself over night. Thanks once again for the input.