Unitherm Governor (U.g.) Replacement; Lo Nox Pool Heaters; Operation; Start-Up Procedures - Raypak 206A Installation & Operating Instructions Manual

UNITHERM GOVERNOR (U.G.) REPLACEMENT

1. Shut water, gas and electricity off, close valves
and relieve pressure.
2. Drain heat exchanger.
3. Remove retainer plug located next to the outlet
pipe connection.
4. Unsnap old U.G. to remove from retainer plug.
Snap in new U.G.
5. Reinstall retainer plug, taking care to lubricate
gasket with a non-petroleum based grease such
as AquaLube.
LO NOx POOL HEATERS
The Lo NOx pool heaters are certified and tested
under the ANSI Z21.56/CSA 4.7 Standard for Gas-
Fired Pool Heaters.
The heater should be installed to meet all local codes,
and the latest editions of the National Fuel Gas Code
Z223.1 and the National Electrical Code, ANSI/NFPA
70.

OPERATION

On call for heat, the ignition system, consisting of an
electronic spark module, gas valve and pilot system, is
energized. Providing the pilot is proven, the blower
will start running, the main gas valve will open and the
heater will operate. When the operating control is sat-
isfied the heater will shut down.

START-UP PROCEDURES

1. Turn on power to the heater with gas supply off.
2. Turn on gas supply.
3. Set controller to call for heat.
4. System should start as follows:
a. Spark will turn on, pilot gas valve will open, and
the blower will begin running.
b. Once the blower provides pressure, the main
gas valve will open.
c. Heater will operate until call for heat is satisfied.
NOTE: Door must be in place for proper operation.
BLOWER ADJUSTMENT
This Lo NOx pool heater is equipped with a combus-
tion air plate (baffle) mounted on the air intake to the
combustion air blower. The baffle has a hole that is uti-
lized to control the air inlet to the blower.
When the combustion air setting is proper, there will be
some lifting of the flames on some areas of the burner
Retainer Plug
U.G.
Spring
Gasket
To test the operation of the Unitherm Governor, place
in hot water (over 110°F) and watch for movement
against spring. If there is no movement, replace unit.
deck under cold-start conditions. After about five min-
utes of operation, the flames should settle down and
blue tips should become visible. Lifting of flames
beyond five minutes would indicate too much combus-
tion air.

VISUAL INSPECTION

Flames can be observed through the opening below
the plenum. Flame color is blue and evenly spread on
the top surface of the burner. At least every three
months a visual inspection should be made of the
burners.

ELECTRICAL

Be sure that electrical service to the heater has prop-
er overload fuse or circuit breaker protection, wire size
and connections which comply with all applicable
codes.

FLAME ROLL-OUT SAFETY SWITCH

Lo NOx heaters are equipped with a thermal cut-off
device to prevent flame roll-out in the event the heat
exchanger becomes blocked. It is a "manual reset"
type roll-out switch that must be reset by a service
technician after any over-temperature conditions have
been fixed. Excessive restriction in the heat exchang-
er flue passage may cause the switch to disable the
heater.
Manual Reset Switch
45