Section 4. Maintenance Instructions; Limiting The Heater; Pressure Relief Valve - Pentair MASTERTEMP 125 Installation And User Manual

Section 4. Maintenance
MAINTENANCE AND CARE
DO NOT interfere with any sealed components. This must be done by a qualified service professional.
1. Inspect the heater panels and venting system to make sure that there are no obstructions to the flow of ventilating
air or burner exhaust.
2. Keep the area in and around the heater clear and free from combustible materials, gasoline and other flammable
vapors and corrosive liquids.
3. If applicable, test the operation of the pressure relief valve by lifting the valve lever. (See below for "PRESSURE
RELIEF VALVE" below.)
4. Test for proper operation of the pressure switch. (See "WATER PRESSURE SWITCH" (page 27) for testing
instructions.)
5. Check pipe and fittings for cracks or breaks. The combustion air blower is permanently lubricated, and does not
require periodic lubrication. The burner does not require maintenance or adjustment by the user. Call a qualified
DE-LIMING THE HEATER
Working with Muriatic Acid can be dangerous. When cleaning elements always wear rubber gloves and eye
protection. Add acid to water, do not add water to acid. Splashing or spilling acid can cause severe personal
injury and/or property damage.
Should a heater require de-liming, this may be accomplished by circulating a solution of 30% Muriatic Acid. This
process should only be performed by a person of sufficient skill. The heater MUST be disconnected from the pool
plumbing, gas plumbing, and electric. The heater may be placed on its side with the water manifold "up". The diluted
muriatic acid may be recirculated until visible bubbles are no longer produced. Before being restored to service, the
heater water ways should be completely rinsed with regular tap water.

PRESSURE RELIEF VALVE

European Standard Codes of Practice may require installation of a pressure relief
valve (PRV). Purchase separately and install a 19 mm (.75 in) pressure relief
valve complying with the local Plumbing Codes, having a capacity equal to the
Mega Joule (MJ/hr) rating of the heater. The relief pressure of the valve MUST
NOT EXCEED 344 kPa.
The relief valve must be installed vertically. To install the valve, use a 19 mm x 89
mm (.75 x 3.5 in) brass nipple at the manifold, the two brass elbows and nipples
are (user supplied), as illustrated in Figure 40. DO NOT place any valve between
the manifold adapter and the relief valve. To avoid water damage or scalding
from operation of the relief valve, install a drain pipe in the outlet of the pressure
relief valve that will direct water discharging from the valve to a safe place for
disposal. Do not install any reducing couplings or valves in the drain pipe. The
drain pipe must be installed so as to allow complete drainage from the valve and
drain line. The relief valve should be tested at least once a year by lifting the
valve lever.
Explosion hazard. Any heater installed with restrictive devices in the piping system downstream from the heater, (including
check valves, isolation valves, flow nozzles, or therapeutic pool valves), must have a relief valve installed as described above.
P/N 475114 Rev. F 8/2020
Risk of fire or explosion from flammable vapors. Do
not store gasoline, cleaning fluids, varnishes, paints,
or other volatile flammable liquids near heater or in the
same room with heater.
WARNING
WARNING
(NOT FACTORY INSTALLED)
WARNING
MASTERTEMP 125 Pool and Spa Heater Installation and User's Guide
Section 4. Maintenance
WARNING
Pressure
Relief Valve
(PRV)
Install brass nipple and
elbow as shown for a
Pressure Relief Valve
(PRV)
Figure 40.
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