HOT WATER CYLINDER

Is the problem ... 

 The hot water cylinder is not working ? 

Guidance:

First check that there is power to the cylinder - has the RCD tripped at the electric consumer unit? Then check your programmer - is the correct date and time set? Have you looked at your water ON/OFF sequence - is is correctly set for the timings when you want hot water? If all appears correct then report it as a defect - all you need do in the description box is quote the code HWCNW and confirm:
* Last serviced date
 (nothing else, no explanation, just this code).

 The hot water cylinder only works intermittently ? 

Guidance:

This sounds more like a programmer issue. Check that you have set the correct date and time. Check the water ON sequence to ensure it is being asked for hot water when you need it. If all appears correct, report it as a defect- all you need do in the description box is quote the code HWCNWI and confirm:
* Last serviced date
(nothing else, no explanation, just this code).

 The water doesn't get hot, just warm ? 

Guidance:

This sounds more like a programmer issue i.e. the cylinder is not programmed for long enough periods. Check that you have set the correct date and time. Check the water ON sequence to ensure it is being asked for hot water when you need it. If all appears correct, report it as a defect - all you need do in the description box is quote the code HWJW and confirm:
* Last serviced date
(nothing else, no explanation, just this code).

 The hot water programmer is not working ? 

Guidance:

Check that you have set the correct date and time. Check the water ON sequence to ensure it is being asked for hot water when you need it. If all appears correct, report it as a defect - all you need do in the description box is quote the code HWPNW (nothing else, no explanation, just this code).