High temperature solar non return valve - NVHT- 15F-15C 

The AVG high temperature solar non return valve provides the necessary protection for the components in your Hot water system and your appliances.
 
In addition to this it ensures the solar hot water system operates efficiently by eliminating thermo syphoning overnight*.
 
As modern solar hot water systems can produce hot water well in excess of 100⁰c the system can come up to temperature very quickly.
 
Water can super heat in the solar collector and make its way back to the tank causing the tank to kettle** or damaging plastic water pipes, pumps, valves.
 
Ensuring an AVG high temperature  non return valve is fitted will allow your system to operate at its optimum while providing the protection required.
 
* A breached non return valve will allow hot water from the tank to make its way up to the collector overnight cooling the system
 
** Kettling which sounds similar to water hammer is caused by super-heated water making its way to the tank this can also be alleviated by the installation of an AVG air eliminator.

At plumbonline we have the full AVG range of valves available here - AVG