222, 223, 622 and 623 Table Drawer Heater System Test and Repair

Use the table below to determine the required action.

Problem Required Action

Drawer heater does not warm up. Heater switch does not illuminate.

Perform Heater Switch Test

Drawer heater does not warm up. Heater switch illuminates.

Perform Heater Plate Test

Drawer heater OK. Heater switch does not illuminate

Replace heater switch.
Meter Reading Status Required Action

Approximately 115 VAC

Thumbs down

Replace switch.

0 VAC

Thumbs down

Switch OK. Check connections and fuses

Drawer Heater System Drawer Heater System

1.Remove heater switch. *Disconnect two incoming power wires.

2.Set meter to 200 VAC.

3.Place meter probes on incoming power wires.

Meter Reading Status Required Action

0 VAC

Thumbs down

Replace switch.

Approximately 115 VAC

Thumbs down

Switch OK. Check Heater Plate.
Equipment Alert

Unplug power cord before removing stirrup guide.

1.Remove stirrup guide.

If necessary, remove chair arm brace. Refer to:Table Shroud Removal.

2.Disconnect two white leads from drawer heater switch to the drawer heater.

3.Set meter to 200 VAC

4.Place meter probes on two white leads from switch.

5.Plug in power cord, then depress switch to ON.

Caution

Unplug power cord before re-connecting electrical leads.

1.Re-connect electrical leads.

2.Replace stirrup guide.

This procedure also applies to the upholstery heater switch.

Heater Switch Replacement

Caution

Unplug power cord before removing stirrup guide.

1.Remove stirrup guide.

If necessary, remove chair arm brace. See Table Shroud Removal.

2.Tag, then disconnect wires from faulty switch.

3.Remove switch housing.

4.Remove switch assembly.

1.Install switch assembly.

2.Install switch housing.

3.Connect switch electrical wires.

4.Replace stirrup guide.

Meter Reading Status Required Action

Approximately 360 Ω

Thumbs down

Heater plate is good.

0 Ω

Thumbs down

Replace heater plate.

1.Remove heater switch. Disconnect two white heater plate wires.

2.Set meter to 2000 (2k) .

3.Place meter probes on heater plate wires.

Drawer Heater Plate Test

Meter Reading Status Required Action

Approximately 360 Ω

Thumbs down

Heater plate is good.

0 Ω

Thumbs down

Replace heater plate.

Caution

Unplug power cord before removing stirrup guide.

1.Remove stirrup guide.

If necessary remove chair arm brace. See Table Shroud Removal.

2.Disconnect two white leads from drawer heater switch to the drawer heater.

3.Set meter to 2000 (2K)

4.Place meter probes on terminals of heater plate wires.

1.Re-connect electrical leads.

2.Replace stirrup guide.

Heater Plate Replacement

1.Remove screw(s) from drawer slides.

2.Push LH slide lever up and RH lever down. Remove drawer.

Slide levers are clear plastic.

3.Disconnect heater plate wires.

4.Remove heater plate.

1.Install heater plate.

2.Route heater plate wires behind slide. Connect wires.

Equipment Alert

If there is not a wire connection here, you must lower table shrouds and remove the top cover in order to disconnect / route heater plate wires.

3.Install drawer.

4.Install screw.