Replacement powerhead mid postion valve honeywell V4073A

[heidibear8]

I have just had a (new) replacement powerhead(40003916-003) fitted to my Honeywell V4073A mid-position valve.
I notice that after the central heating turns off, the powerhead remains very hot. The package info mentions that the powerhead will remain warm, but mine remains HOT indefinitely with a faint electrical vibration. Should this powerhead remain hot despite the pipes around it having cooled? The powerhead only cools off after the hot water has been on.
I also have a second problem with the powerhead. Last night was very cold and the Frost Stat (Sunvic TLM 2257 Frost Thermostat) in the attic kicked in. Instead of the central heating switching on, the hot water was triggered. The powerhead's "last port of call" had been the hot water position, but shouldn't the powerhead have automatically switched to the central heating position when triggered by the Frost Stat?
Is my new replacement powerehead faulty?
Any advice will be much appreciated

 

[gavinda]

no it fires to last port. plus you wouldnt really want heat in the middle of the night.

all sounds normal.

 

[heidibear8]

Frost stat is needed if we are away. Don't want the pipes in the attic/house to freeze. Shall have to make sure the hotwater is not the last port of call before we go away. I wonder if the general public are aware of this?
Is it normal for the powerhead to remain very hot to the touch after the heating port of call and to remain so indefinitely unless the hot water is the last port of call?
Thanks so much

 

[gavinda]

the frost stat is just a precaution. when you are away id still advise the heating is left on. i generally reccomend heating is left on 24 hours setting with the room stat on 10 degrees. the froststat is no guaruntee to not allow the house to freeze. it just stops the boiler freezeing due to its location.

boilers in the garage or an outhouse i suppose?

 

[heidibear8]

No, the 2 gas boilers are in the house, in the utility room. I usually leave the heat on for two hours early morning and two late evening while we are away. The house is a large old stone one and it would cost a fortune to leave the heat on all the time. There is no central thermostat, the boilers seem to be triggered by the radiators settings in each room. The frost stat is in the attic, which also contains a large water tank. Even when the heat is on most of the day, if it gets below freezing at night the frost stat set at 5C in the attic kicks in as the attic cools off quickly (it has a stone roof and the insulation is on the floor)!
Bit of a dilema what to do!
Thanks for your time.