M series do not have a drain. When we install these, we usually put a drain near the heater
so it can be drained without having to disconnect any of the hoses. If you have to disconnect one at the heater
, be very careful of the hose barb on the pump
. It is plastic, and if you break it, you have to replace the whole pump (and they are expensive).
The drain we have used lately is a spirotrap drain., like this:
TDN075-FT - Spirotherm TDN075-FT - 3/4" Spirotrap Drain Brass Dirt Separators with removable head (Female Thread)
It is designed as a trap for particles, and with a valve on either side you can drain out the sump in it without draining the whole system.
Originally Posted by DavefromNZ
No one? Oh dear, do we all have the same problem building up and no easy solution?