Frozen hot water pipe

grumpycrab

-12degC last night - left CH on but woke up with a frozen hot water pipe (2 HW taps off one run). Pipes are all lagged - 1st time frozen - not sure what to do.

Leave them or put some heat in the loft space where the pipe runs?

southcoastrgi

my advice would be to go into the loft & make sure the frozen pipe hasn't split, because if it has then it won't be leaking due to the ice blocking the hole, but when it thaws it will, hopefully that hasn't happened & it's just frozen if it is take the lagging off & use a hairdryer to thaw it, if it has split turn off the water to that pipe & repair or get it repaired (much easier while you haven't got water pouring through the ceiling), best of luck

grumpycrab

Thanks - examined as much of the pipe that I can get too -looks ok. Put fan heater in space...fingers crossed...

roger196

Make sure that defrosted pipe if split does not leak onto fan heater. Use rcd.
Make sure you have a fire extinguisher readily available.
Have you checked there is no combustible material near fan heater or could be blown near to it.

grumpycrab

Pipe unblocked after about 30mins with heater in space near pipe- fan heater location was safe.

Although the pipe was lagged it was near a North facing vented soffet (spelling?) and (I guess) -12deg got to it. Although space was tight I've added some extra insulation (but there's still plenty of ventilation), so should be OK. (Temp forecast is not that bad tonight.)

27col

If a pipe freezes in the roof then it is not insulated well enough. This is also borne out by the fact that a bit of local heating has thawed the pipe. Alternatively, the loft floor is too well insulated and is letting the loft space get really cold
It is normal practice to leave the area under the water tanks uninsulated, to allow a small bleed of heat in the area where water pipes are to be found.
You can buy pipe insulation that is twice the normal thickness. A small investment in some of this might be money well spent.
You don't want to be having the trouble and expense of sorting the consequences of a burst pipe. I once knew someone who had a pipe burst in the loft while they on holiday, and the resultant bill came to £14,000