Boiler not heating water cylinder

Bigdig69 · 14-04-2021 10:33pm #1

My Ideal gas boiler is 3 years old. When it was installed, the hot water cylinder was also replaced. Today the heating is working as normal but the cylinder is cold.

Any suggestions as to potential problems/fixes?

John.G · 15-04-2021 7:16am

Is the system zoned, ie have you separate motorized valves for CH and HW?.

Bigdig69 · 15-04-2021 10:28am

No, it is not zoned. There is a room thermostat on the landing I am not sure if that could be relevant.

John.G · 15-04-2021 11:25am

The cylinder will then only heat while the room stat is actually calling for heat as the stat will start/stop the boiler, are the cylinder coil flow and returns hot while the boiler is actually firing?

Bigdig69 · 15-04-2021 1:15pm

As you can probably tell I am a bit clueless here. Thanks for your help.

There is a cold pipe connected to the bottom of the cylinder. About halfway up the side, there is a pipe that is hot. At the very top, there is a pipe that is SLIGHTLY warm. Usually, our water is very hot.

John.G · 15-04-2021 3:25pm

The red arrow is pointing to a automatic air release valve (AAV), there should be a a small cap on this like a car valve dust cap, unscrew this and remove it and see if any air comes out with boiler in service, when/if water comes out, put the cap back on.
Can you take a photo looking from the right onto all that cylinder pipework.

Bigdig69 · 15-04-2021 5:18pm

Thanks I will try this later.

John.G · 16-04-2021 7:28am

Also have a look (or photo) of the valve marked in red a bit further down. it looks like a lever type ball valve with lever removed and looks as if its partially open/closed, a 1/4 turn clockwise is fully closed a 1/4 turn anticlockwise is fully opened. Suggest fully opening it and then later close it in a bit as this acts as a balancing valve to stop the cylinder coil robbing all the circulating hot water from the rads.

Boiler not heating water cylinder

Comments