I have just replaced the faulty 25 year old TA/M4 valve on my heating system with a Drayton MA1/679-3 mid-postion valve. The TA/M4 connected to a RB 2 relay. Do I still need the relay? I have connected to the relay in the same way as the TA/M4 was but the MA1 does not energise (or is the...
