Fill And Test Water System; Purge Air From Water System; Check Thermostat Circuit(S) - Pioneer PHR100-55 Instruction Manual

2. Freeze protection fluid must be replaced periodically due to degradation of inhibitors over time. Follow
all fluid manufacturer instructions.
C. FILL AND TEST WATER SYSTEM
1. Fill system only after ensuring the water meets the requirements of this manual.
2. Close manual and automatic air vents and heater drain valve.
3. Fill to correct system pressure. Correct pressure will vary with each application.
a. Typical cold water fill pressure for a residential system is 12 psi.
b. Pressure will rise when heater is turned on and system water temperature increases.
Operating pressure must never exceed 25 psig.
4. At initial fill and during heater startup and testing, check system thoroughly for any leaks. Repair all
leaks before proceeding further.
5. The system may have residual substances that could affect water chemistry. After the system has been
filled and leak tested, verify water pH and chlorine concentrations are acceptable.
D. PURGE AIR FROM WATER SYSTEM
1. Connect a hose to the purge valve and route hose to an area where water can drain and be seen.
2. Close the heater or system isolation valve between the purge valve and fill connection to the system.
3. Close zone isolation valves.
4. Open quick-fill valve on cold water makeup line.
5. Open purge valve.
6. One zone at a time, open the isolation valves. Allow water to run through the zone, pushing out the air.
Run until no noticeable air flow is present. Close the zone isolation valves and proceed with the next
zone. Follow this procedure until all zones are purged.
7. Refill to correct pressure.
E. CHECK THERMOSTAT CIRCUIT(S)
1. Disconnect the two external wires connected to the heater thermostat terminals (low voltage terminal
strip).
2. Connect a voltmeter across these two incoming wires with power applied to thermostat circuits. Close
each thermostat, zone valve and relay in the external circuit one at a time and check the voltmeter
reading across the incoming wires.
3. There should NEVER be a voltage reading.
4. If a voltage does occur under any condition, check and correct the external wiring. (This is a common
problem when using 3-wire zone valves).
5. Once the external thermostat circuit wiring is checked and corrected if necessary, reconnect the
external thermostat circuit wires to heater low voltage terminal strip.
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