Non Central Heating - Hot water fine

[Wondering_Aloud]

Hi All,

I need a bit of advice with non-functioning central heating while the hot water still works. The boiler isn't in my house so I'm not 100% familiar with it and it's the first time it's really been used since about last April.

If I turn the hot water on at the controller, the boiler kicks in. However, if I turn the hot water off and then turn the heating on, you can hear the relay in the controller click, but the boiler doesn't kick in. If you turn the thermostat, you can hear the switch inside it click and a multimeter applied to the terminals shows that the thermostat is switching the supply voltage to the bolier.

At first, I thought 3 way valve although finding it it's proving very difficult. The boiler's a back boiler behind a fire on the living room so I'm guessing it could be built in to that but in the past, when I've had a 3 way valve fail, both the heating control and the hot water controls still managed light the boiler, the radiators just didn't get very hot.

Now comes the fun part as the house was struck by lightning in August so I'm wondering of something has fried. Given that the controller seems to switch fine and the thermostat seems to switch, I'm not sure where to start.

Any suggestions? .

Thanks in advance.

 

[stem]

Unfortunately, you don't give any meaningful details of the system.

If it's an antiquated system with gravity circulation of hot water and pumped central heating (ie one without a motorised valve). It is necessary to have the hot water on before the heating will operate. It's not possible to have just the heating on alone. Generally the programmer is configured so that whenever the heating is required, it switches the hot water on too. - Try switching the hot water on first and when that's on try the heating.

On the other hand if you have a Y-Plan system with a 3-Port motorised valve, then that is responsible for controlling the boiler when the heating is required but not the hot water alone, so the valve could be faulty. An S-Plan system with two 2-Port motorised valves is slightly different.

So unfortunately you will need to provide a much more detailed description of the system before anyone can provide specific help.

 

[Wondering_Aloud]

Hi,

Thanks for replying. I must admit that I'm a bit in the dark on the exact layout of what we have. I'm familiar with my own setup, but this one is at a relative's house.

I will have a go with both heating and hot water on to see if that makes a difference and will get back.