Hi,
I have an old unvented cylinder in my flat and I've only ever used\needed the topup heater (top thermostat). I've tried the bottom one which supposedly heats up more water as it's lower, but doesn't seem to. As a comparison the top heater will get the water up to temperature then switch off and stay off for about 15 minutes. Then switches back on for about 2 minutes heating the water again and so on.
But the bottom heater switches off, then only stays off for about 30 seconds, then comes on for a about a minute, then off for 30 seconds and so on (this is without any water running so no extra cold water coming in)
Any ideas why this would be? I can only guess there's so much sediment in the bottom that the heater is basically trying to heat that and not the surrounding water and maybe needs a cleanout?
Thanks
I have an old unvented cylinder in my flat and I've only ever used\needed the topup heater (top thermostat). I've tried the bottom one which supposedly heats up more water as it's lower, but doesn't seem to. As a comparison the top heater will get the water up to temperature then switch off and stay off for about 15 minutes. Then switches back on for about 2 minutes heating the water again and so on.
But the bottom heater switches off, then only stays off for about 30 seconds, then comes on for a about a minute, then off for 30 seconds and so on (this is without any water running so no extra cold water coming in)
Any ideas why this would be? I can only guess there's so much sediment in the bottom that the heater is basically trying to heat that and not the surrounding water and maybe needs a cleanout?
Thanks