LAARS Rheos RHCV - Install and Operating Manual - Manual (Page 39)

Rheos Boiler and Water Heater Page 39
6. Switch on the appliance power switch located on
the front of the unit.
7. The Rheos will enter the start sequence. The
blower and pump come on for pre-purge, then
the ignitor warm-up sequence starts and after all
safety devices are verified, the gas valve opens. If
ignition doesn’t occur, check that there is proper
gas supply. Wait 5 minutes and start the unit
again.
8. Open air orifice test port valves. Check air
orifice differential at full fire, and make note of
the differential.
9. Switch the Rheos off.
10. Close air orifice valves, remove the barbs and
replace the plugs. Make sure the connections are
gas tight.
11. Remove the two plugs from the + and – ports of
the gas orifice taps, thread hose barbs into the
1/8" NPT connections, and attach the manometer
pressure lines to the barbs. Be sure all
connections are gas tight.
12. Switch on the appliance power switch located on
the front of the unit.
13. The Rheos will enter the start sequence. The
blower and pump come on for pre-purge, then
the ignitor warm-up sequence starts and after all
safety devices are verified, the gas valve opens.
14. Open gas orifice test port valves. Check gas
orifice differential at full fire, and make note of
the differential.
15. Close gas orifice valves, remove the barbs and
replace the plugs. Make sure the connections are
gas tight.
16. If gas and air orifice differentials match what
is shown in Table 10, and do not differ from
eachother by more than 0.1" w.c., the unit is
properly set up. If not, consult, the factory.
17. After placing the appliance in operation, the
Burner Safety Shutoff Device must be tested.
To test:
(a) Close gas shutoff valve with burner
operating.
(b) The flame will go out and blower will
continue to run for the post purge cycle.
One additional attempt to light will follow
including pre-purge, ignitor on, valve/flame
on and post purge. Ignition will not occur
as the gas is off. The ignition control will
lockout, and will have to be reset before the
unit will operate.
(c) Open gas shutoff valve. Restart the
appliance. The ignition sequence will
start again and the burner will start. The
appliance will return to its previous mode
of operation.
Valve
Valve
Shown
Open
Closed
Shown
Figure 34. Gas/Air Test Panel.
Figure 35. Test Panel Valves.