Too many other things on in the no-rain warm days. Anyway, in terms of progress on this, I made a suitable spanner to shift the gate valve nuts. Band sawed the sides and chain drilled the two angles in a 1/2" thick piece of steel that enabled me to get in with a hammer. I don't know the correct name for the through-pipe that the motor connects to but I got it off. It was 26/1/07 when I felt I had no choice but to get someone in quickly with a poor circulation problem and a large organization said yes. After a couple of hours of scratching his head, I had to instruct him to change the pump in the end. Amongst other things, I told him things like gate valves were never set fully open; just a half-turn back. He decided that one gate valve was not fully open at all and all but screwed the head of it! He had not cleaned up the gate valve surfaces of the original fiber washers at all and about half of each was still there. The rubber washers he stuck in were squashed paper-thin in places but it fixed the fault. He didn't seem to comprehend that.
I don't like things I don't understand so I rooted out the original pump (This is the Grundfos 18/60-130 of 1983-4 vintage) which I vaguely remembered taking apart and there were some loose bits in the impeller and concluded that a foreign body had got in somehow. With new-found ideas, I tested it's capacitor labelled 2.5uF +/- 5% and it was down to 1.95uF so that was quite probably the original fault. Some options have opened up with a proven 2.48uF capacitor out of the useless motor to hand, but not on sunny days.
Johntheo5, I have read your previous mail several times and I don't fully comprehend it. It is a fact that on one occasion of the trials I had the UPSO15-60 CESA02 motor in and no resulting circulation at all. The motor had water in it (repeated venting on it's screw) but I didn't even have the hot water circuit working. There is a vent after the HW control valve effectively above and venting the HW tank.
The vent is the expansion pipe back to the header tank, straight up through the airing cupboard. That tees of horizontally, then down 90 degrees to the pump on a short bit of 3/4" bent pipe with both control valves (HW & CH) within a foot after the motor.
I don't like things I don't understand so I rooted out the original pump (This is the Grundfos 18/60-130 of 1983-4 vintage) which I vaguely remembered taking apart and there were some loose bits in the impeller and concluded that a foreign body had got in somehow. With new-found ideas, I tested it's capacitor labelled 2.5uF +/- 5% and it was down to 1.95uF so that was quite probably the original fault. Some options have opened up with a proven 2.48uF capacitor out of the useless motor to hand, but not on sunny days.
Johntheo5, I have read your previous mail several times and I don't fully comprehend it. It is a fact that on one occasion of the trials I had the UPSO15-60 CESA02 motor in and no resulting circulation at all. The motor had water in it (repeated venting on it's screw) but I didn't even have the hot water circuit working. There is a vent after the HW control valve effectively above and venting the HW tank.
The vent is the expansion pipe back to the header tank, straight up through the airing cupboard. That tees of horizontally, then down 90 degrees to the pump on a short bit of 3/4" bent pipe with both control valves (HW & CH) within a foot after the motor.