Hi everyone. My plumber installed a new immersion cylinder for me and advised me to install a thermostat on the copper pipe. Currently my immersion is wired via an immersion switch. The neutral and earth i understand. I have one live feed coming ino my switch and two lives comig from switch to immersion, one for sink, one for bath. I was just wondering how to wire in the stat. I have three terminals in the stat marked C, 1, and 2. Thanks.
“Hi everyone. My plumber installed a new immersion cylinder for me.”
Looking again at Willis system that would seem to fit the description as the immersion heater does fit in a cylinder next to the main cylinder.
“And advised me to install a thermostat on the copper pipe.”
This seems odd as the two thermostats are fitted one in the immersion heater unit in a pocket designed for the job and second (or more) on the side of the main cylinder at a height allowing the amount of water for 4.5 litres for hand-washing, baby’s bath, shaving, breakfast dishes etc. or for washing-up dinner dishes, medium sized clothes wash. Or for a shower or for a bath. So 4.5l, 9l, 14l or 54l of hot water can be selected which of course is the advantage of the Willis system.
“Currently my immersion is wired via an immersion switch. The neutral and earth i understand. I have one live feed coming into my switch and two lives coming from switch to immersion, one for sink, one for bath. I was just wondering how to wire in the stat. I have three terminals in the stat marked C, 1, and 2. Thanks.”
Well C and L1 are used for heating water and L2 is used to control the motorised valve in a central heating system but thermostats with change over switches are normally rated at around 6A where the immersion heater uses 13A.
It is common to combine heating systems with the Solasyphon, central heating and the immersion heater all having the option of being used. The normal for the immersion rather than using extra thermostats is to use a timed amount of power with 5 minutes, to 1 hour to provide the amount of water required when the main heating is not running.
It seems the same questions has been asked before I seem to remember answering this before so it may be worth scrolling to find other answers.
The sad story of babies death (Google "telegraph.co.uk/news/uknews/1575026/Council-aware-of-boiler-fault-that-killed-baby.html") means we must look very hard before installing a system that all the parts are compatible. Although the thermostat was blamed with solid fuel heating it is common for water to boil and if non resettable over temp devices were used one would be forever changing thermostats because the water had boiled and with solid fuel a resettable type is used. Also of course a far stronger cistern able to handle boiling water without failure.
In view of this I would ensure you get the work done by some one who knows what they are doing not a fly by night Plumber who does half a job and rides off into the sunset!