7
2.2 Start-up Procedure for RediHeat Water
Heaters with Recirculation Systems
The following procedure should be used when starting the
RediHeat fitted with a forced recirculation loop system.
This procedure will be applicable in systems with either a
fixed thermostatic element diverting valve, or the adjustable
thermostat diverting valve.
Note:
Before starting up a RediHeat incorporating
a recirculation system, carefully read:
SECTION 5 -
RECIRCULATION SYSTEMS.
This section covers how the
recirculation system should be correctly piped up.
1. With the circulating pump “off”, set the RediHeat water
outlet temperature as described in 5 & 6 of section 2.1
Initial start-up.
2. Check that the temperature indicator has been placed
in the correct position to measure the temperature in
the return line to the users. Now start the circulating
pump. With all faucets “off”, observe the temperature
of the recirculated water.
3. Typically the diverting valve is set 10ºF below the
normal set temperature of the RediHeat. Because
diverting valves are less accurate than the water heater,
temperature variations up to 10ºF may be experienced
in the loop temperature.
4. If an adjustable diverting valve has been fitted, the
recirculated temperature should be adjusted with all
faucets “off”, after the piping system has had time to
stabilize.
Section 3
Maintenance
3.1 Blending Valve Disassembly
Refer to Section 4 of this manual for troubleshooting.
Disassembly of the blending valve need only be undertaken
if problems in performance or instability of temperature is
linked to the blending valve. Be sure all work is performed
in a clean environment to prevent the introduction of foreign
matter into the valve mechanism. Part numbers below refer
to the cross sectional drawings found on pages 31 and 32
in Section 7 Drawings, of this manual.
Procedure
1. Close all steam and water supply lines.
2. Disconnect the sensing tube (46) from the lower valve
body (42 or 43) and diaphragm cover (5). (Note position
of notch in cover relative to the valve body.)
3. Disconnect Victaulic couplings at all valve connections
and remove the valve.
4. Loosen and remove casing bolts (14) and lift off the
diaphragm cover.
5. Hold the upper stem (1) by placing wrench on flats.
Remove jam nuts (7) taking care not to turn the stem.
Remove shouldered washer (8) and O-ring (9) along
with diaphragm (13), diaphragm plate (11), spring (10)
and guide washer (16).
6. Inspect diaphragm for any cracks or tears.
7. Remove retaining clip (19) from the temperature control
rod (18). Unscrew the locking ring (21) and remove
cover plate (22).
8. Compress the circlip (23) and remove from adjusting
sleeve (27). Remove temperature control rod (18) and
adjustor key cylinder (25).
9.
Caution:
Do not permit valve plug to drop from lower
valve body. Hold valve stem (1) from above.
10. Unscrew retaining screw (35), remove spring (36), and
spacer washers (37 & 38).
11. Remove the valve plug assembly through lower
housing.
12. Remove socket head cap screws (12) and lift off lower
diaphragm case (5) Remove O-ring (15) taking care not
to damage groove.
13. Unscrew cap screws (49) and remove lower valve body
(42 or 43).
14. Push black teflon coated temperature-adjusting sleeve
(27) out of upper valve body (17).
15. Remove main valve stem (1).
Notes:
a) Inspect all parts for wear or damage. Replace all
gaskets and O-rings.
b) Clean, flush and dry with clean cloth.
c) See parts list for recommended overhaul parts. Gaskets
and O-rings should be replaced during any repair
procedure.
3.2 Blending Valve Re-assembly
Procedure
1. Install the temperature adjusting sleeve (27) into the
upper valve body (17).
2. Assemble upper valve body (17) to lower valve body (42
or 43) and secure cap screws. Note the cold water inlet
will be on same side as the control rod opening.
3. Insert main valve stem (1) into bottom of temperature
adjusting sleeve (27) and push until the collar washer
seats against upper valve body.
4. Insert valve assembly into adjusting sleeve (27) and
push until it is fully seated.
5. On lower end of valve stem install spacer (2), washer
(37), bearing washer (38), spring (36), and tighten
retaining screw (35).
6. Install O-ring (15) in groove on upper valve body and
