water tank overflowing

[wildmind]

Hi guys,

I'm having issues with my water heater.

I have a tank with two immersion heaters. Basically, when it's been on for more than an hour and a half, water comes out of the expansion releif valve.

Once I turn off the water and run a hot tap, it stops. What tests can I do on the expansion tank to make sure it's working?

thanks

 

[Goldberg]

Is it a Megaflo unvented cylinder?

 

[kevplumb]

megaflo

 

[bass]

sounds like it needs recalibrating.

 

[kevplumb]

Is it a Megaflo unvented cylinder?

read the book have we