Ariston Heaters manual Reference Number

Pipe	Connect the cold water inlet pipe to the inlet nipple (marked with a blue ring - #1, Fig. 4).
Connections	IMPORTANT: You must use dielectric fittings if inlet piping/fittings are copper or brass.
	Failure to provide dielectric insulation may result in premature tank or nipple failure and will
	void warranty. Dielectric nipples are recommended over unions and are available from a
	supply house or CEC.
Caution	To	reduce the risk of excessive pressures and temperatures in this water heater, install
	temperature and pressure protective equipment required by local codes but not less than a
	combination temperature and pressure relief valve certified by a nationally recognized
	testing laboratory that maintains periodic inspection of production of listed equipment or
	materials, as meeting the requirements for Relief Valves and Automatic Gas Shut-off
	Devices for Hot Water Supply Systems, ANSI Z21.22. This valve must be marked with a
	maximum set pressure not to exceed the marked maximum working pressure of the water
	heater. Install the valve into the opening provided and marked for this purpose in the water
	heater, and orient it or provide tubing so that any discharge from the valve will exit within 6
	inches above, or at any distance below, the structural floor, and cannot contact any live
	electrical part. The discharge opening must not be blocked or reduced in size under any
	circumstances.
Closed	Periodic discharge of the temperature and pressure relief valve or failure of the element
system	gasket may be due to thermal expansion in a closed water supply system. The water utility
thermal	supply meter may contain a check valve, backflow preventer or water pressure reducing
expansion	valve which will create a closed water system. During the heating cycle of the water heater,
	the water expands causing pressure inside the water heater to increase. The temperature
	and pressure relief valve may discharge hot water under these conditions which results in a
	loss of energy and a build-up of lime on the relief valve seat.
	To prevent this from happening, there are two recommendations:
	1.	Install a diaphragm-type expansion tank that is suitable for potable water on the cold
		water supply line. The expansion tank must have a minimum capacity of 1.5 U.S.
		gallons for every 50 gallons of stored water.
	2.	Install a 125 PSI pressure relief valve in the cold water supply line. Make sure the
		discharge of this valve is directed to an open drain and protected from freezing.
		Contact the local water supplier or plumbing inspector for information on how to
		control this situation. Do not plug the temperature and pressure relief valve.

Fig. 2 Components Parts

REFERENCE NUMBER

1 - Cold water inlet 1/2" - NPT marked blue 2 - Hot water outlet 1/2" - NPT marked red

3 - 3/4" NPT female tapping for relief valve

4 - Temperature & pressure relief valve, 3/4" NPT. Make sure that the probe of the T&P valve is no longer than 4".

5 - Temperature & Pressure relief valve discharge line to drain

4