Mexico Super 3 boiler, new pump is BG Multihead G. CH has two zones, upstairs and down. Pipe splits after pump to honeywell valves for upstairs CH and HW. switches on both these valves moving OK and set to auto.
Pipe to downstairs zone appears to bypass pump?? it's downstairs radiators that...
On returning from holiday CH and HW not coming on. BG man diagnosed pump gone and replaced. Now HW on all the time, regardless of whether timer on or not. Also radiators warm, regardless of thermostat setting or timer setting.
Any ideas??