Boiler heating towel rails even through all controllers off

[PolH]

I'm trying to work out why my towel rails are always hot and the boiler is running even though I have all hot water and central heating controls turned off.

Vaillant ecoMAX 600
Ariston tank
Hot water from the tank
1 main controller
Underfloor heating with 2 manifolds with controllers
Analogue wall thermostats in each rooms
2 heated towel rails - basic valves, no thermostats

I have both manifold controllers turned off (temp <5)

The main controller has central heating turned off and hot water to come on twice a day.

However I've noticed that the towel rails are always hot and the boiler lights up heating something - I presume the towel rails.

I had an engineer in for another issue and he told me that the towel rails were used to disperse excess heat? Which makes no sense to me.

Any assistance would be appreciated.

 

[electronicsuk]

Even if the towel rads are piped such that they bypass the zone valves and controls, they should only be hot when DHW or one of the heating zones is demanding heat from the boiler. They certainly shouldn't be hot all the time.

I suspect you have a wiring issue or a sticking microswitch on one of your zone valves, causing the boiler to be on 24/7.

 

[Boilerman2]

Yuo probably have a dedicated Towelk rail heating circuit and has been said the Two port valve controlling the loop is probably stuck open