Cheapest way to heat loft just enough to prevent frozen pipes

TuppenceHapenny

Lorian wrote: »

It would have to be winter for the loft to be cold enough to freeze, and then you'd want to be fixing your boiler quickly anyway?

Yes, you're right - I would want it fixed quickly. But I don't have one of those on-going boiler care contracts because I feel they are not good value for money and I know that getting a heating engineer out at short notice can be difficult and/or expensive. So if I can all but eliminate the risk of a frozen pipe by no more than the cost of some electric lamps or a cheap electric heater and a thermostat I would rather do that so I've got time so sort out the boiler repair (and heat the house with a gas fire/ electric radiators in the meantime).

TuppenceHapenny

sevenhills wrote: »

Maybe leaving a tap running would be the cheapest option, although it might not affect all pipes.

Yes it would certainly help but I wouldn't want to rely on it given what is at stake (and as you say some pipes in the loft would not be affected)

EssexExile

That must be some big pilot light if it raises the temperature in the loft significantly.

Heedtheadvice

Electric pipe trace heating tape.
Designed for the job
Low power
Heat where it is needed
Self thermostatically controlled
Cheapish outlay
Very cheap to run.


Not a recommendation but an example

https://www.frostprotection.co.uk/12w-m-self-regulating-trace-heating-cable?gclid=EAIaIQobChMIxuLYqr6L3QIVLrXtCh31aA10EAQYAiABEgJOjPD_BwE

stator

My pipes to the loft all go through the airing cupboard. So using an electric heater in the airing cupboard would keep some heat in the pipes. They aren't lagged in the airing cupboard because I want them to absorb heat. They are lagged in the loft. Also the top of the airing cupboard isn't insulated well, so heat from there does leak into the loft where the water tank and pipes are

TuppenceHapenny

EssexExile wrote: »

That must be some big pilot light if it raises the temperature in the loft significantly.

It's just a normal boiler pilot light. And it really does raise the temperature in my loft enough to prevent frozen pipes (though I suppose it may not be true for all houses). I was as surprised about it as you when I realised.
I'm sure there must be plumbers or the like out there who know about this and could confirm that it is true (for some houses at least).

TuppenceHapenny

Alter_ego wrote: »

I used 2x40w lightbulbs coupled via a thermostat to do the same thing in a boat. Successful over 9 winters where the canal usually froze one month a year.

I would be interested to know how you determined the number and wattage of light bulbs required.

that

TuppenceHapenny wrote: »

I would be interested to know how you determined the number and wattage of light bulbs required.

Would think the boat is sealed tighter, and may have a smaller volume, more compartmentalised?

Put 10 or so bulbs in, it does not really matter. if the wattage of 10 is too much the thermostat turns off sooner, and if you put 2 bulbs in it will take at least 5x longer to heat up using a similar amount of power. if the roof is not heat tight the losses of the two bulbs may not be enough to turn of the heat and they could be on for much longer

Anther way is to put a greenhouse fan heater up there - think you get 2kw ones, but with large air leaks and draughts you may only end up heating the heavens.