Hot water not very hot

[koootzz]

Glow worm spacesaver 40 mkII
The hot water is only getting warm, can put my hand in. I have checked that the boiler cuts in, it does, the pump is running, the in pipe into the cylinder is hot but the out is cold. I suspect an air lock in the cylinder or pump is on it's way out. How do I check, could there be anything else and if the cylinder is airlocked, how do I get the air lock out.
Thanks

 

[corgigazza]

What controls the hw temp, cylinder stat + 2/3 port valve(valve not opening), tap stat(TRV pin stuck), blue cyltrol valve on outlet may have hw return gate valve close to much

 

[koootzz]

there is no cylinder stat, only stat is on boiler, have turned this up to full. Have checked zone valve (this only switches heating on and off) and is working OK. I don't know about the tap stat or blue cyltrol valve, how do i find and check these?

 

[B.O.B DOLE]

how is the ch

 

[corgigazza]

are there any valves between the zone valve and the flow out of the cylinder pipework(red handled gate valve) , run the hw only rads should stay cold may be airlock.

 

[koootzz]

there are no valves between the cylinder and the zone valve. Haven't tried th ch yet

 

[koootzz]

I've tried the ch, radiators get hot, so can't be the pump? I have drained down the system (with the zone valve open), refilled slowly bleeding pump and radiators as it filled. Tried again, got ch but pipes going into cylinder are still cold. Did hear a few bubbles through the expansion pipe when I switched to hw only but then nothing.

 

[B.O.B DOLE]

there is no cylinder stat, only stat is on boiler, have turned this up to full. Have checked zone valve (this only switches heating on and off) and is working OK. I don't know about the tap stat or blue cyltrol valve, how do i find and check these?

it might be switching ch on and off but it might not be moving over to dhw

 

[koootzz]

the only thing that i can see that controls hot water/ch is the 2 way zone valve, i cannot have ch on without hot water so i assume that this is the only control on the system. Could the coil inside the cylinder still have air in it, if so how do i remove it(i have drained down once). Could it be blocked somehow?
Is there a plumber in the s.derbys area that would like to come and have a look?

 

[GuinnessJPG]

the only thing that i can see that controls hot water/ch is the 2 way zone valve, i cannot have ch on without hot water so i assume that this is the only control on the system. Could the coil inside the cylinder still have air in it, if so how do i remove it(i have drained down once). Could it be blocked somehow?
Is there a plumber in the s.derbys area that would like to come and have a look?

 

[liverpoolboy]

What controls the hw temp, cylinder stat + 2/3 port valve(valve not opening), tap stat(TRV pin stuck), blue cyltrol valve on outlet may have hw return gate valve close to much

blue control valve on outlet? I have never heard of this before? There shouldn't be any controls on the h/w return ! confusing reading this post!