Recent content by ramchip

Hi mrgas, I think you must be confusing it with lower output models (6-10 and 10-16), which don’t have the pump over-run feature. The 16-22 certainly does; in the original installation manual it’s called ‘pump delay’ on terminal block connection 4. Later versions of the 16-22 have this on...

Thanks ChrisR. I appreciate what you say about one of the MVs being constantly held open using one relay. I’ll have a think tonight to see if I can get round it using two as you suggest. True the boiler ain’t broke … so no need to fix it! Back in Feb. it was a different story and the old...

The boiler is a very old but still capable Potterton Netaheat Mk 2F (16-22). No sign of any bypass pipework. The boiler flow goes directly to the pump. The output from the pump goes to the rads and the cylinder coil via MVs. (There’s a T-junction in the pipe from the pump) One solution would...

...the zone valves are shut so the hot water in the heat exchanger is not circulating as it ought to. Once heating demand is satisfied the 2-port spring return motorized valves (MVs) close, hence no circulation. The wiring diagram in the boiler manual doesn't make any allowance for this, so...