My heating is currently not working properly, the hot water is working fine though. It is quite an old system, Thorn EMI back boiler, with hot water cylinder upstairs and header tank in the loft. It has a 3 way Honeywell divertor valve. The boiler is firing up when heating is selected on the programmer. I had a similar problem last year and I replaced the syncron motor on the valve and it fixed it. I could not replace the valve head as it is an old valve. The thing is this time I am not sure if the pump is actually operating. We have these pumps on hot water systems at work and you can feel vibration when they are running, mine just appears to be doing nothing. To make it worse I do not think that it has isolation valves either side of it. Although it does have small protuding heads on the fittings on each side of the pump that may require some kind of key, but I am not so sure that they are valves. Has anybody got any ideas how to check the pump please, or any other pointers. Any help would be greatly appreciated