Short cycle after a long cycle why?

[bayliner]

Hi Guys

i have just installed a new Honeywell homexpert thermostat, I set it to do 3 cycles per hour of 4 mins. This keeps the house at a nice temp. But just recently after 6 days of installing the stat, it will do a 15 second cycle just after it finishes it long cycle. I would say it happens more just after the heating programme kicks in and then just reverts back to the long cycles after a couple of hours.

Is there a reason why. It never did it before

thanks in advance

Paolo

 

[Ermintrude]

Overrun

 

[kay-jay]

as ermi says it is pump overrun.
a feature designed to dissipate the heat.

 

[bayliner]

Thanks, so nothing to worry about then. As mentioned this does stop but after a couple of hours of the heating programme being on, I guess when the house is nice and warm.

thanks

paolo

 

[bayliner]

Sorry just to clarify the pump stays on but also the boiler is firing up for 10-15 seconds after it's longer cycle and then you hear the valve closing.

paolo