no hot water unless the central heating is on.

[daf]

my heating and water is through a danfoss randall 3033. you can have the water and heating on at the same time or just one or the other off or both off either on auto or manual. for some reason the water does not heat up now unless the heating is also on. do i need a new timer or is it something else?

[fasc]

try turning the thermostat to zero and putting your heating on this should just give you a hot tank of water without your heating coming on. you should do this in the summer months.  i used to have a randal but i dont know if it is the same model so goodluck daf