Where to place a thermostat on HW cylinder

[Nephin]

Hi folks.

We recently got a new 250 litre 3 coil hot water cylinder installed.
The tank thermostat is located near the the bottom of the tank and the water never gets warm enough there for the thermostat to switch off the motorised valve that feeds the hot water to the tank.

Where is the best location on the tank to put the thermostat?

Thanks.

 

[45yearsagasman]

1/3 the way up from the base is ideal. Set it to 60c.

 

[ALEC1]

what are the other two coils doing, and indeed what is the top coil doing...?

 

[Nephin]

what are the other two coils doing, and indeed what is the top coil doing...?

Top coil is from stove back boiler which is what we use the most.

The second coil is connected to the oil boiler.

The third coil is connect to solar panels.

 

[mysteryman]

Presumably the cyl stat is controlling the heat source to one of the coils? The thermostat should be a little above the coil it controls, and not straight above the flow connection into the coil.

The old 'one third of the way up' rule was OK for gravity primaries, but it is not a 'one size fits all' rule for pumped primaries or multiple coils.

 

[PlumbGas]

Presumably the cyl stat is controlling the heat source to one of the coils? The thermostat should be a little above the coil it controls, and not straight above the flow connection into the coil.

The old 'one third of the way up' rule was OK for gravity primaries, but it is not a 'one size fits all' rule for pumped primaries or multiple coils.

Couldn't agree more, if 1 coil then 1/3 up is correct, however your main source of heat is to the top coil and as heat does not travel down then the bottom of the tank will not get hot,