System boiler always calling

[Kilted Scot]

Hi All,

I have a logic s30 boiler with hot water tank, 2 diverter valves and programmer. All just over 2 years so out of warranty.

up until recently everything worked great, now a small issue.

If I set programmer for heating only works great.

I I set programmer for hot water, either with or without heating, the boiler will run but no actually burning or heating. However, if I use the hot water and tank realises the need and calls then the boiler will flame and work as normal.

it is like the fan or pump is constantly running when activated by programmer.

I m considering going down hive route, but obviously need make sure system is working first.

BTW I can still get heating and hot water as required.

thanks

KS

 

[ianmcd]

sounds like you have an external control fault, do you have an S plan or a Y plan system, pics of everything you have are best

 

[Kilted Scot]

S-plan, 2 motorised valves , 1 for heating and 1 for hot water.

 

[ianmcd]

Sounds like you have a sticking end switch on one of the valves

 

[Kilted Scot]

Thanks Ian,

I never thought of the motorised valve, they are danfoss hpa 2, so I am guessing then the switch is permanently closed and testing by the orange grey would confirm?

 

[ianmcd]

Thanks Ian,

I never thought of the motorised valve, they are danfoss hpa 2, so I am guessing then the switch is permanently closed and testing by the orange grey would confirm?

yep when the motor is fully engaged,it makes the end switch , this signals the boiler to fire (makes the grey and orange) both switches are wired together, making the valve manualy open does not make the end switch, but they are prone to sticking, very cheap parts

 

[Kilted Scot]

Thanks Ian,

so now confused,

traced to the wiring centre, disconnected the aux circuit on HW valve, and tested the boiler and all worked so, replaced the HW actuator, danfoss hpa2 so complete actuator,

restested system and still have the same fault.

totally confused dot com

Please any further ideas that may help

 

[ianmcd]

To be honest your post is very confusing, have you changed any wiring ? The prime suspect would be the Cylinder thermostat, definately an external control fault somewhere or wiring fault, its not tha boiler and no changing to Hive wont solve the problem , you will have to sort the problem then fit hive,it is simply two switches exactly the same as you already have