Replacement CH Controller for SANGAMO M5

I currently have a noisy Sangamo M5 CH controller and am looking to replace it with a digital programmer(7 day) type. I currently have a pumped CH system and gravity fed HW system.

I would be grateful of any advice regarding a suitable replacement for the controller without modifying any plumbing.

its not down to the plumbing, its down to the wiring behind the clock. pretty much anything out there will fit but annoyingly the m5 doesnt have any markings on the back of it so you wont know what the wiring currently is. not a problem for us but could be for you if you are not confident.

Thanks for replying!

I have downloaded the sangamo M5 manual and I should be able to identify the wiring ok.

You say pretty much everything will fit so is there anything I should be avoiding is the vast majority of these controllers will fit my requirements.

Would be interested to hear from others who have changed this controller.