Laars Rheos RHCH, Installation And Operation Instructions Manual, Page: 40 / 60

LAARS Heating Systems
Page 40
SECTION 7.
Maintenance
WARNING
Disconnect all power to the appliance before
attempting any service to the appliance. Contact
with electricity can result in severe injury or death.
7.1 System Maintenance
1. Lubricate the system water-circulating pump, if
required, per the instructions on the pump.
2. If a strainer is employed in a pressure reducing
valve or the piping, clean it every six months.
3. Inspect the venting system for obstruction or
leakage at least once a year. Periodically clean
the screens in the vent terminal and combustion
air terminal (when used).
4. Keep the appliance area clear and free from
combustible materials, gasoline, and other
flammable vapors and liquids.
5. If the appliance is not going to be used for
extended periods in locations where freezing
normally occurs, it should be isolated from the
system and completely drained of all water.
6. Low water cutoffs, if installed, should be
checked every 6 months. Float type low water
cutoff should be flushed periodically.
7. Inspect and clean the condensate collection and
disposal system yearly.
8. When a means is provided to neutralize
condensate, ensure that the condensate is being
neutralized properly.
9. Inspect flue passages, and clean with brushes/
vacuums, if necessary. Sooting in flue passages
indicates improper combustion. Determine the
cause and correct.
10. Inspect the vent system and air intake system,
and ensure that all joints are sealed properly. If
joints need to be resealed, completely remove
existing sealing material, and clean with alcohol.
Apply new sealing material, and re-assemble.
7.2 Appliance Maintenance and
Component Description
Only genuine Laars replacement parts should be
used.
Caution
Label all wires prior to disconnection when servicing
controls. Wiring errors can cause improper and
dangerous operation. Verify proper operation after
servicing.
Caution
Should any odor of gas be detected, or if the gas
burner does not appear to be functioning in a
normal manner, close main shutoff valve, do not
shut off switch, and contact your heating contractor,
gas company, or factory representative.
Gas Type
Air Orifice Gas Orifice
Differential Differential
Natural
4.0 to 4.5" W.C. 4.0 to 4.5" W.C.
(1.0 to 1.1kPa) (1.0 to 1.1kPa)
Propane
4.5 to 5.0" W.C. 4.5 to 5.0" W.C.
(1.1 to 1.2kPa) (1.1 to 1.2kPa)
Note: Long runs of vent or combustion air piping may
reduce the air and gas differential pressures. This is
acceptable, as long as the pressures are within 0.1"
(0.025kPa) w.c. of each other.
Table 10. Air and Gas Orifice Differentials at Full Fire.
6.3 Shutting Down the Rheos
1. Switch off the main electrical disconnect switch.
2. Close all manual gas valves.
3. If freezing is anticipated, drain the Rheos and
be sure to also protect building piping from
freezing.
This step to be performed by a qualified
service person.
6.4 To Restart the Rheos
If drained, follow Section 6.1 in this manual
for proper filling and purging.
1. Switch off the main electrical disconnect switch.
2. Close all manual gas valves.
3. WAIT FIVE (5) MINUTES.
4. Set the aquastat or thermostat to its lowest
setting.
5. Open all manual gas valves.
6. Reset all safety switches (pressure switch,
manual reset high limit, etc).
7. Set the temperature controller to the desired
temperature setting and switch on electrical
power.
8. Burner will go through a prepurge period and
ignitor warm-up period, followed by ignition.