Economy 7 Immersion Heater Problem.

23 Nov 2012
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United Kingdom
Hello There, wonder if anyone can give me some advice as I am at a loss as to what to do next. I have a single element immersion heater on Economy 7 that is controlled via a radio transmitter signal from Scottish Hydro. Recently the water was not heating properly, only ran hot for a short time then went cold. As the tank and element were fairly old we decided to replace as initially thought the element was failing. So new element and thermostat. However still getting the same problem. We have a Horstmann E7 BX control panel but this only has a boost function no timer on it. If I switch on the boost the water heats up lovely. Have checked the resistance of the coil (reading 20ohms) and also checked the thermostat circuit. All fine. I have two separate meters, one Is just for the storage heaters and immersion heater. I don't use the storage heaters but tested them last night as I thought maybe the signal to the radio transmitter was not coming on but the storage heater worked fine. Really at a loss as to what the problem is now....Anyone help? I would really appreciate any thoughts on this. Thanks
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Thanks for posting so quick EFLImpudence, much appreciated. The Horstmann I have is just a simple panel with no timer controls. This is the product synopsis from a website that sells them..

These simple controls are intended for use where cheap overnight heating of water is controlled by the Electricity Company's Radio Teleswitch, Radio Telemeter or tariff time switch.
Simple to install and use
Boost period adjustable between 0 and 120 minutes
Neon indicator shows when boost timer is running
Can be used with one or two immersion heaters
Compatible with earth-leakage circuit breaker installations
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So maybe try changing out for a new Horstmann and see if that does the trick. Thanks

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