Formerly Jim's Plumbing


What is a Uni-Control or Unitrol Valve?

Let's discuss the purpose of a Robertshaw uni-control (or unitrol) valve. This is a temperature sensor that controls the temperature and thermostat, connected to a thermocouple that holds down the pilot.

This system is also equipped with a sacrificial anode to protect from rusting and calcium build up – these should be checked every 3-4 years.

Gas storage 135-litre hot water systems contain uni-control valves. This gas hot water system has two components including the uni control which controls the temperature within the unit.

This valve offers fast and precise execution when heating water.

Including being equipped with 2 magnetic strips that hold the pilot in place once the temperature is achieved, the bi-metal strip inside the control valve opens up allows the flow of gas through the pilot tube and within in seconds ignites burner.

This will continue to run until the temperature is reached at what the valve is set at. These fast-tracking sensors continuously check the water temperature while they are in operation.

For instance, as soon as a tap is turned on and water flows through an outlet in the house, cold water begins to enter at bottom inlet point and drops the temperature which, in turn, causes the dedicated sensors to start heating the unit until the temperature is reached again.

The tank also has a sacrificial anode which covers the entire centre of the tank. This should be changed at intervals of 3-4 years to extend the life of the tank.

Problems that can arise with these units are as follows:

  • Faulty thermostats that continually heat can cause extreme temperatures plus also the hot and cold valves can actually continue to run.
  • If temperature relief valves fail they can cause pressurising in the tank which can cause the tank to rupture and explosions to occur.
  • The uni-control valve has an ECO (integrated and non-cyclical power interruption) – an energy cut switch which is for safety reasons.

Contact Plumber Near Me for all hot water system maintenance, repairs and installations. If your water is not heating properly, give us a call.

Convenient interest free** payment plan options are available on hot water heater replacements to help ease any financial stress this burden may cause.

We can often have a plumber to customers’ homes within the hour*.

Please note: This information is provided for advice purposes only. Regulations differ from state to state, so please consult your local authorities or an industry professional before proceeding with any work. See our Terms & Conditions here.