Frost Protection Valves

Frost Protection Valves for solar panels

American-made frost protection valves for solar hot water services.


Don’t risk losing one or more of your solar collectors from a random frost.

Buy a reliable, top quality, American-made frost valve to ensure frost protection for years to come.

We sell this brand because we have found other brands have a short service life, or they become unreliable, and leak.

Half inch frost protection valve

Half inch frost protection valve

Valve starts to open when the valve senses fluid temperature nearing 3.9 oC.    Valve will be fully open at 1.6 oC.   As the fluid temperature rises again the valve will close.

Three quarter inch frost protection valve

Three quarter inch frost protection valve

Do you realise how many hundreds of dollars damage a single frost can cause to your solar water heater collectors?    Going unprotected can cause major inconvenience, as well as losing all your stored hot water, once the frost has thawed.   Simple installation of this device can mean the difference between a major disaster, and trouble-free operation.

How does it work?

In cold, frosty weather, the frost valve opens when the roof temperature drops to about 3 or 4 degrees, allowing water that would normally freeze inside the exposed solar collector, to be discharged and replaced with warmer fluid coming from within the system.   When the warmer temperature water is detected by the thermal actuator within the frost valve, it will automatically close the valve and stop the discharge.     This cycle will repeat as often as is necessary, usually overnight,  to prevent freezing.   The amount of fluid discharged depends on ambient air temperature, and the fluid temperature.   The system is functioning properly when fluid is being discharged from the valve, in near freezing conditions.  (About 3 to 4 degrees). 

Will I lose a lot of water?

Typically, the frost valve will only discharge a small trickle of water, for a few minutes.   As soon as the warmer water is detected, the frost valve shuts.   This action may occur several times on a really cold night, but isn’t losing a few litres of water occasionally, much better than replacing solar collectors?   

What makes it work? 

We stock replacement frost protection valves, as originally supplied by many manufacturers, for many years.    The quality solar panel frost protection valves are made of brass, and have been found to be the most reliable, with a long service life.   These frost valves have been successfully used over many years to protect thousands of solar water collectors from occasional mild frosts.   The valves have a 3/4″ male BSP thread for easy fitting.   Adaptors and special fittings are available to suit different manufacturers’ panels, if required.   This type of freeze protection valve uses a reliable, non-electric, self-contained paraffin wax thermal actuator, which automatically responds to temperature fluctuations.

Features and Benefits.

  • Easy installation.
  • No noise, no power use
  • Protects all water-filled solar systems
  • Drains freezing water only when there is frost
  • Energy and water saving
  • Very long life


Prices :  13 mm (1/2 inch) :  $169 each

              20 mm (3/4 inch) :  $178 each

Same day express-post available to anywhere in Australia or New Zealand


Order now, or ask a question:

Queensland:    (07) 5448 8304      qld at

Victoria:            (03) 9808 7337      vic at

or use this form:

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