Hot water turning on issue

[Helpful]

i have a hot water tank and gas boiler and for the last 4 months my boiler turns on when I use some of my hot water like it’s reheating the bit I just used.

This wouldn’t normally be an issue but my entire heating system is set to off for the summer.

How or why is my boiler reheating the hot water when everything is turn off.

 

[Aire]

So you have a twin channel timer and both your heating and hot water settings are turned off?

 

[Helpful]

Yes both setting are off

 

[Aire]

Do you have 2 zones valves or a 3 port valve?

 

[Helpful]

I’m pretty sure it’s a Honeywell 3 port valve as my heating is only one zone

 

[Aire]

If you do have a 3 port, then this valve sits in the hot water position when powered off, so that would lead to me think you have a fault with your programmer. It may be set to off but could still be sending power to the cylinder thermostat. When you use your hot water, the temp in the tank drops causing the stat to call for heat which will then bring your boiler on. This is only one possible cause though so I'd recommend you get a plumber out to check the system and electrics over.

 

[Helpful]

I did wonder if it was the programmer but then I also wondered whether it was the actuator that had broken and was stuck. You’re right the a plumber coming is the best option I did want to change to a nest setup soon anyhow so maybe I’ll do it sooner than I planned
Thxs for your help

 

[Harvest Fields]

Get a heating engineer to do a fault find. It maybe cheaper in the long run.