Bradford-White Corp 500-1825 Maintenance, To Turn Off Heater, To Shut Down System, Indoor Models

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Pilot Reset

Switch

Figure 17. Pilot Safety Relay.

When a tank aquastat is not used:

The pump on the heater must run continuously, so the heater's temperature control will sense the tank's water temperature. Set the heater temperature control to the desired tank temperature. Set the manual reset high limit 50°F higher than the heater temperature control. Example: If desired temperature is 140°F, set the heater temperature control at 140°F, and set the manual reset high limit at 190°F.

3.4 To Turn Off Heater:

1.Turn off main electric switch.

2.Close all manual gas valves.

3.5To Shut Down System:

To shut down heater, turn off all manual gas

valves and electrical disconnect switches. Whenever danger of freezing exists, shut off water supply and remove drain plug in the bottom of front header cover. Drain every part of system subject to freezing temperature.

SECTION 4.

Maintenance

1.Lubricate the water circulating pump (see instructions found on the pump).

2.If a strainer is employed in a pressure reducing valve or in piping, clean it every six (6) months.

3.At start-up and every six (6) months thereafter, the pilot and main burner flame should be observed for proper performance (see Figure 18). See attached lighting and shut-down instructions for proper pilot flame pattern). If flame has the appearance of “sooting” tips, check for debris near orifices. Call serviceman.

4.Inspect the venting system for obstruction, leakage and corrosion at least once each year.

Figure 18. Main Burner Flame Pattern.

5.Keep heater area clear and free from combustible material, gasoline and other flammable

vapors and liquids (see Table 1 for minimum clearances).

6.Be certain all combustion air and ventilation openings are unobstructed.

7.Check for fouling on the external surfaces of the heat exchanger every six months. (NOTE: After installation and first start-up, check the heat exchanger for fouling after the following periods of operation: 24 hours, 7 days, 30 days, 90 days, and once every six months thereafter).

Fouling on the external surfaces of the heat exchanger is caused by incomplete combustion and is a sign of combustion air and/or venting problems. As soon as any fouling is observed, the cause of the fouling should be corrected (see Section 5, Troubleshooting Guide). The heat exchanger can be checked by locating a mirror under the burners with a flashlight. An alternate method is to remove the venting and top panel as necessary to inspect from above. Also check the vent system for defects at this time.

a.If cleaning is required, shut off all electrical and gas supply to the heater.

b.To expose the heat exchanger:

Indoor Models:

Remove flue pipe, top of unit, rear upper jacket, flue collector rear panel and heat exchanger baffles.

Outdoor Models:

Remove vent top assembly, rear upper jacket, flue collector rear panel and heat exchanger baffles.

c.Remove all burners:

It is usually more convenient to remove the burner tray assembly. Disconnect sensor wire, ignition cable (or thermocouple generator) and pilot gas line. Disconnect manifold inlet union(s). Remove the four

(4) retaining screws. Grasp burner/pilot assembly firmly at the front. Push it back, disengaging it from the gas orifice. Lower the front of the burner (to avoid damaging pilot shield) then remove the burner tray.