dont want to sound like an old school teacher but Pressure and temperature are directly proportional so as the pressure decreases so does the temperature so the higher the draw off the lower the temperature hence the freezing
Went out and bought a new regulator valve this morning and a gas engineer was in the shop mentioned that it had a small 'air balance' hole in the side which would fill with water if it was fitted upside down and that if it froze in the cold weather it would cause the regulator to shut down.
Looking at my existing one it had been fitted 'side on' so possibly with all the rain we have had of late and cold weather, water may had got in and frozen.
We live and learn eh?
Thanks again for your help guys, you have been brilliant.
If you need to find a tradesperson to get your job done, please try our local search below,
or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Please select a service and enter a location to continue...
Are you a trade or supplier? You can create your listing free at DIYnot Local