Cheapest way to heat loft just enough to prevent frozen pipes

TuppenceHapenny

I know from bitter experience that the rising heat from the pilot light (yes, pilot light) of my gas boiler is enough to prevent frozen pipes in the loft in normal winters. So I want to find an equally cheap heat source I can use to warm the loft just enough in the event of the boiler not working.

The cheapest thing I've found so far are electric caravan/shed heaters (e.g. 55W heater). Would one of these be likely to work and are there cheaper alternatives (I don't want any naked flames because of the fire risk and yes, the pipes in the loft are already lagged)?

sevenhills

TuppenceHapenny wrote: »

The cheapest thing I've found so far are electric caravan/shed heaters (e.g. 55W heater). Would one of these be likely to work and are there cheaper alternatives (I don't want any naked flames because of the fire risk and yes, the pipes in the loft are already lagged)?

An Incandescent bulbEmits light through the heating of a small metallic coil called a FilamentSurrounded by gases that heat to approximately 4000 F! While providing plenty of light, they release 90% of their energy as heat making them fairly inefficient in comparison to compact fluorescent lamp bulbs.


You could always just leave the loft hatch open? I need to repair the plastic/rubber sheets in my roof, as it is torn and lets in a severe draught.

casper_g

If you really need to keep the temperature above freezing, then a 55W heater will probably be unable to achieve this in an uninsulated loft when it's really cold outside. A heater of whatever power without an effective thermostat will either waste energy by making the loft hotter than it needs to be, or will fail to keep the loft warm enough.

So, you want a higher powered heater with a decent thermostat. Maybe something like this? https://www.screwfix.com/p/dimplex-coldwatcher-electric-heater-500w/97670

getmore4less

Remove the insulation under the pipes and stick extra over then.

No point heating a whole loft when it is just the space around a pipe that need to be kept a bit warm

that

I would think that the lamp and heater energy would go straight up, or be blown away unless you have an insulated roof?

But the bulbs may initially be the cheapest, but not the most cost effective over the long term?

me, would rather
remove pipe insulation
go for a thermostat and I would set it around 3-5C mehanical should work, but I would get an Inkbird ITC308 as they are cheap to thermostat turn-on temperature: +3°C; - turn-off temperature: +4°C
https://www.ebay.co.uk/itm/Inkbird-ITC-308-Digital-Temperature-Controller-thermostat-Heat-Cool-control-220V/223007204692?epid=1160999577&hash=item33ec43e554:g:kNsAAOSwQTVa6msz
At the coldest end I would attach the thermostatic sensor on the pipe
Then wrap a heating element around the pipe but not over the thermostatic sensor. Then cover all this with pipe insulation.

https://www.ebay.co.uk/itm/Electric-underfloor-heating-loose-cable-kit-all-sizes-in-this-listing-GLS/231880118978?hash=item35fd21d2c2:m:mEMOUq4kw3Y0UTAjrm627Dw

https://www.ebay.co.uk/itm/20m-Minco-12K-33-Ohm-m-Carbon-Fiber-Underfloor-Heating-Cable-Floor-Warming-XBUK/142720673428?epid=16008336812&hash=item213ad0a694:g:6l4AAOSwC8FZbBQd

https://www.amazon.co.uk/Elektra-Frost-Protect-Freezing-Condensate/dp/B00HQEX2BC/ref=pd_sbs_86_23?_encoding=UTF8&pd_rd_i=B00HQEX2BC&pd_rd_r=d591da6a-a930-11e8-b7b1-1f841b9564db&pd_rd_w=ghYcw&pd_rd_wg=9BTvR&pf_rd_i=desktop-dp-sims&pf_rd_m=A3P5ROKL5A1OLE&pf_rd_p=85d62760-2a0e-407d-aa36-f3c03afc01c3&pf_rd_r=PC5V0E9ATMM8G990P9QV&pf_rd_s=desktop-dp-sims&pf_rd_t=40701&psc=1&refRID=PC5V0E9ATMM8G990P9QV

https://www.amazon.co.uk/Reptile-Vivarium-Propagator-Heat-Cables/dp/B002P1PWN2/ref=sr_1_14?ie=UTF8&qid=1535288769&sr=8-14&keywords=pipe+heat+cables

Alter_ego

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.

Old_Git

I always leave the loft hatch open .just a couple of inches .

Lorian

getmore4less wrote: »

Remove the insulation under the pipes and stick extra over then.

No point heating a whole loft when it is just the space around a pipe that need to be kept a bit warm

That's the MSE way to do it :-)

TuppenceHapenny

Thanks for all replies.

Just to clarify, I'm thinking of a situation where the gas boiler is not working (so no central heating and no pilot light) and so the only ways of heating the house are with a gas fire or electric radiator(s). When the house is empty (e.g. when everyone is at work) or at night (when everyone is asleep) I would not want to leave the gas fire on for safety reasons and would not want to leave electric radiator(s) turned on because of the cost. So the house would have periods when it is completely unheated and there is no boiler pilot light turned on.

At present having no heating even for extended periods is not a problem because the boiler pilot light is always on and keeps the loft permanently safe from frozen pipes. So I'm wondering what is the cheapest way to prevent frozen pipes in the rare situation when there is no boiler pilot light. From replies so far it looks like it would be a choice between a small(ish) electric heater controlled by a thermostat or else using the heat from one or more electric light bulbs - presumably in lamp(s) placed on top of the gas boiler to mimic the heat produced by the pilot light when on(?)

Apologies for the original post not being clear.

Lorian

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?

sevenhills

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