I have a Telford Direct 900mm x 450mm copper cylinder with 1xbacker Kw 240V type 311 and 1xbackersafe 3Kw 240V ~2.76Kw 230V type BS311C immersion heaters. I noticed the water getting progressively cooler over a period of a couple of days until it was just plain cold. I have since turned off the switches (economy 7 and regular) to save power. The problem is that I can't find replacement heaters (as specified above)anywhere online and don't know what would make an acceptable replacement. I would like to replace them with something that had an integrated thermostat and timer to better control my electricity consumption. I am also planning to have a pump installed as my water pressure is abysmal, but this will increase my consumption of hot water in the long run as my electric shower will be replaced with a shower mixer. I don't know if this will impact on the type of immersion heater I require. Thanks forum readers, any advice really appreciated.
the pump shold not effect your immersion heaters. if open vented (has cisterns in roof space) watch out that you have enough capacity up there for the booster set.
are you sure the heaters are kapoot. on some heaters there is a high limmit switch. looks like a round bit o broass with two insulated wires cumming from it, and a small red pin between them. try pushing the pin in. make sure the innersion stat is set to 60-65 degrees centigrade.
could be a thing called "one pipe circulation"
the first fitting off the hot draw should be a compression elbow, NOT A T' peice. the pipe should then go horizontally 450mm before the T' for your vent and hot draw.