Removing dhw heat exchanger

[b21playa]

Hi all

I have a Vaillant Ecotec 837 which rumbles only was hot water running, been told it would be a blocked plate exchanger.

I’ve purchased some new seals but wondered how I go about removing it, do I need to drain the system, turn off cold mains and unscrew the 4 screws?

Thanks in advance

 

[terryplumb]

What do you mean by " rumbles only was hot water running " ? Are you getting hot water at constant temperature at taps ? If you do want to remove the plate hex ,read thru the service manual ,which will give you the way to do it. ( largely as you have outlined , and electrically isolate first )