The immersion will warm your water but if it's really cold it won't stop hoses from freezing you need the water to circulate throughout the whole system as if your working,mine won't click in until it's needed or below 2 degrees comes on for 12 minutes and turns itself off. 3 grand well spent it's only just over a
Weeks work Dave lol
Of course it stops the hoses from freezing. For less than £100. What's not to love about it?