More Hot Water Problems

[brizzlewolf]

Please excuse the lack of correct terminology etc but basically I have a problem with hot water when the control is switced to hot water and heating. The water does not heat quickly enough or reaches an acceptble temp (although it is warm). When the water only control is selected the water will heat but takes a long time 2/3 hours. If I use the immersion heater this will take 20/25 mintes from cold. The inlet to the coil is red hot but the outlet stone cold. There is some sort of solenoid operated valve piped into the outlet pipe prior to its retun to the boiler.
The central heating is fine an warms very quickly.

 

[bones001]

check a gate valve on the return pipe from your cylinder coil isnt partially shut off

 

[jobloggs]

Solenoid operated valve is a 2 port valve. Plenty of posts on here about these but your problem is that it is probably not opening when it should to allow water to flow through the coil. It should be controlled by a thermostat about 2/3 the way down the outside of your cylinder. This could be faulty and not calling for the zone valve to open.

There is a manual lever on the zone valve which allows you to open it. Try that first to see if you get flow through the cylinder. That will at least tell you whether you have an internal blockage or closed gate valve elsewhere. However as indicated above the problem is most likely the zone valve.

Checking the thermostatic valve and the electrics is quite involved and if you call someone in they will probably just change the valve or its motorised head as this is the most likely problem.

If you want to research further there is plenty on this site and the internet if you search on zone valve or 2 port valve.

 

[brizzlewolf]

Thanks for your help. I did switch the valve to manual open and left it for approx 30 mins yesterday but no noticable change. The outlet pipe was still cold.
Is this a blockage in the coil? - I don't see any isloation valves in the pipe runs between the coil and boiler. If it is a blockage what are the possible solutions. I have used descaler and preventer in the system for the past 5 years.

 

[bab]

whats the boiler make, is it gravity hot water or fully pumped. what size pies go to the cylinder & have u got a cylinder stat,

 

[brizzlewolf]

Its a Worcester Oil fired boiler, boiler room model. There is a cylinder thermostat. Pretty sure its gravity hot water. I'm not at home so I can't tell for sure but I think there are inlet and outlet pipes for the coil. Hot water at the top of cylinder and cold water feed at the bottom.