by ericmark »
Fri Jul 14, 2023 7:58 am
As said, landlords problem.
However the main reason for a timer is when you have off peak power, the idea is an immersion near bottom of tank works during off peak times, and one near top is set to lower temperature can cuts in when you run out of water heated with off peak.
In many homes the off peak has been discontinued, you paid more for peak when you have the option for off peak, the idea was to supply storage radiators during off peak, it didn't really work, and you can't stop heat leaving radiator only slow it down, so by the evening very little heat left, And your heating home all day,
There were some high rise flats when after Ronan Point were not allowed gas, and the off peak was the only real alternative, but with heat pumps today and batteries the off peak power is in the main too expensive, so the immersion heater may not need a timer any more.
I heat my DHW four times a week for 1/2 hour at a time, as no thermostat on my tank, so only control I have for the central heating boiler is time, but once hot my water will stay hot for two to three days, I turn off boiler so the pipes between the boiler and the tank are allowed to cool, but in the main with an immersion heater you just let the built in thermostat control it, not need to switch it on/off manually except when going on holiday. 40 gallons takes a long time to cool.
The other reason for twin immersion heaters is you only need the bottom one when you want a bath, so most of the time only top one used, the bottom one switched on couple of hours before you want a bath, a timer is unlikely to help with that.
In Ireland they have a very clever system the willis heater which heats the water from the top down, so a timer is used to maintain the desired level of hot water, but it seems in mainland UK we are too tick to work out how to do that, it's only found in Ireland.
