We have a Worcester 14/19 CBi downstairs with a cylinder upstairs. We've suddenly lost our hot water, but the CH still works fine.
Googling around the subject, this immediately sounds like a motorised valve failure. When I adjust one of the room stats upwards, the "demand" light on the boiler comes on and it fires up, and then shuts off when the temp is reached. However, there's never a response from the boiler when I run a hot tap. Should the "demand" light come on then as well?
If it's a valve failure, is there any way to identify which one, and then manually force it to provide hot water rather than CH?
There are three motorised valves in the upstairs cupboard along with the cylinder - a Honeywell 272848 on the horizontal input pipe from the boiler to the cylinder, and two Drayton ZA5's on vertical pipes running up the wall to the side of the cylinder. They all seem to be two-zone valves with just A and B, no midpoint positions, and they're all on A.
Googling around the subject, this immediately sounds like a motorised valve failure. When I adjust one of the room stats upwards, the "demand" light on the boiler comes on and it fires up, and then shuts off when the temp is reached. However, there's never a response from the boiler when I run a hot tap. Should the "demand" light come on then as well?
If it's a valve failure, is there any way to identify which one, and then manually force it to provide hot water rather than CH?
There are three motorised valves in the upstairs cupboard along with the cylinder - a Honeywell 272848 on the horizontal input pipe from the boiler to the cylinder, and two Drayton ZA5's on vertical pipes running up the wall to the side of the cylinder. They all seem to be two-zone valves with just A and B, no midpoint positions, and they're all on A.
Last edited: