American Water Heater 505 warranty Troubleshooting, Wiring Diagram, U287-1185, Outdoor 305

Fig. 1 Fig. 2

Fig. 3	Fig. 4
Fig. 5	Fig. 6

Troubleshooting

Important Safety Notes

There are a number of (live) tests that are required when fault finding this product. Extreme care should be used at all times to avoid contact with energized components inside the water heater. Only trained and qualified service technicians should attempt to repair this product. Before checking for resistance readings, disconnect the power source to the unit and isolate the item from the circuit (unplug it).

(SV1, SV2, SV3 and POV) Gas valve and Modulating solenoids: (Set meter above 2K)

Wire color	Voltage	Resistance	Connector #	Pin #'s
(Main) Pink - Black	11 ~ 13 VDC	36.8 ~ 44.8 ohms	H5	6	- 7
(SV1) Black - Yellow	11 ~ 13 VDC	36.8 ~ 44.8 ohms	H6	5	- 6
(SV2) Black - Blue	11 ~ 13 VDC	36.8 ~ 44.8 ohms	H7	4	- 6
(SV3) Black - Brown	11 ~ 13 VDC	36.8 ~ 44.8 ohms	H8	3	- 6
(POV) Pink - Pink	2 ~ 15 VDC	67 ~ 81 ohms	H3	9	- 10

(M) Water Flow Control Device Servo or Geared Motor:

Red - Blue	11 ~ 13 VDC	22 ~ 28 ohms	F7	9	- 10
Grey - Brown	4 ~ 6 VDC	N / A	F7	5	- 7
Grey - Yellow	N / A	N / A	F7	5	- 8

NOTE: The grey wire listed above turns to black at F connector on the PCB. (QS) Water Flow Sensor:

Black - Red	11 ~ 13 VDC	5.5 ~ 6.2 K ohms	F2	1 - 3
Yellow - Black	4 ~ 7 VDC	1 ~ 1.4 Mega ohms	F2	2 - 3

By-pass Flow Control (By-pass servo model ONLY):

Brown - White	2	~ 6 VDC		G1	1 - 5
Orange - White			15 ~ 35 ohms	G1	2 - 5
Yellow - White	(Unit in operating mode)			G1	3 - 5
Red-White - Ground				G1	4 - 5
(IG) Ignition System:
Grey - Grey	90 ~ 110 VAC		N / A	C1	1 - 2
(FM) Combustion Fan Motor:
Red - Black	6	~ 45 VDC	N / A	E1	1 - 2
White - Black	5	~ 10 VDC	9.2 ~ 9.4 K ohms	E1	2 - 4
Yellow - Black	11 ~ 13 VDC		3.5 ~ 3.9 K ohms	E1	2 - 3

Set your meter to the hertz scale. Reading across the white and black wires at terminals 2 and 4 you should read between 60 and 420 hertz.

Thermal Fuse / Overheat Switch:

Red - Red	11 ~ 13 VDC	Below 1 ohms	F6	F6 - H12
			H1

Flame Rod:

Place one lead of your meter to the flame rod and the other to ground. With the unit running you should read between 5-150 VAC. Set your meter to the ∝ amp scale and series your meter in line with the flame rod. You should read 1 ∝ amp or greater for proper flame circuit. In the event of low flame circuit remove the flame rod and check for carbon or damage.

Heat Exchanger and Outgoing Water Temperature Thermistors:

Check all thermistors by inserting meter leads into each end of the thermistor plug. Set your meter to the 20 K scale and read resistance. Applying heat to the thermistor bulb should decrease the resistance. Applying ice to the thermistor bulb should increase the resistance. See below for examples of typical temperatures and resistance readings.

Example:		59°F = 11.4 ~ 14K		140°F = 2.2 ~ 2.7K
		86°F = 6.4 ~ 7.8K		221°F = 0.6 ~ 0.8K
		113°F = 3.6 ~ 4.5K
Outgoing Water Thermistor:
White - White	N / A		See example above		F5	3	- 4
Heat Exchanger Temperature Thermistor:
Pink - White	N / A		See example above		F4	3	- 11
Intake Air Thermistor (Indoor model ONLY)
Orange - White	N / A		See example above		F3	3	- 12
Surge Protector:
Black - White	108 ~ 132 VAC		N / A		D2	1	- 3
Blue - Brown	108 ~ 132 VAC		N / A		D1	1	- 3

With the power off you can check the continuity through the surge protector. Place a meter lead on the top pin #1 of the surge protector and pin #3 on the bottom of the surge protector. Check across the top pin #3 and bottom pin #1. If you read continuity across these two points then the surge protector is good. If you do not get continuity then replace the surge protector.

Remote Controls:

Terminals B1 10 ~ 13 VDC 1.5 ~ 3.0 K ohms B 1 - 3

Frost Protection:

This unit has frost protection heaters mounted at different points to protect the water heater from freezing. The heaters located on the hot water outlet line should have a resistance reading of 180-207 ohms through each of these heaters. The heater located on the heat exchanger piping should have a resistance reading of 156-180 ohms and the one located in the water flow sensor valve should have a resistance reading 24-28 ohms.

Amp Fuses:

This unit has one inline (3) amp glass fuses. Remove the fuse and check continuity through it. If you have continuity through the fuse then it is good. Otherwise the fuse is blown and must be replaced.

Wiring Diagram

G1

COLOR CODING

BY-PASS SERVO MODEL ONLY

W :White

BR

BK:Black

BY-PASS FLOW

O

BR:Brown

Y

CONTROL DEVICE

R

R :Red

W

for 2-Unit Connection

BL:Blue

Y :Yellow

FREEZE PROTECTION

G

(Optional)

P :Pink

OPTION

R

O :Orange

WATER FLOW

F1

W Y O RBR

G

G :Green

SENSOR

F2

GY:Gray

5

1

QS

R

R

(CN7)

Y

Y

MODULATING VALVE

BK

BK

MAX

INDOOR MODEL ONLY

MIN

CURRENT ADJUSTING

W RBK

Dip SW1

F3

F

A

AIR TEMPERATURE

O

RBK

G Y

O

1

W

3

1

2

THERMISTOR

W

F

3

W

O

13

1

(CN9)

F

4

5

HEAT EXCHANGER

F4

P

BL BR

WW

(CN5)

6

W

7

Gas pressure

W

8

THERMISTOR

W

P

R Y

Dip SW2

Gas type

F5

1

OUTGOING WATER

O

2

Spare Parts Only

W

W

3

THERMISTOR

F

4

5

F7

W

W

E

F

6

R

GY

H

B

4

1

BL

R

12

(CN2)

1

B1

BR

BL

1

Y

Y

BK

REMOTE CONTROLLER

GY

BR

(CN12)

Y

R

BK

WATER FLOW

W

BK

P

P Y

BR Y

3

W

E1

(CN1)

R P

BK BL

CONTROL DEVICE

FM

Y

BK

COMBUSTION FAN

R

C

SPARK

C1

ELECTRODE

GY

GY

THERMAL FUSES

F6

IG

GY

GY

R

R

IGNITER

R

R

(CN4)

505 305

The original PC boards on the water heaters do not have the bank of 6 dip switches. Only spare PC boards have this bank.

Models 305 and 505 have a default maximum temperature of 120°F (49°C) and an option to increase the maximum temperature to 140°F (60°C). Temperature settings from 125-140°F (52-60°C) are available by setting dip switch 6 to ON in the SW1 bank of 8 dip switches.

Adjust switches 2 and 3 in the bank of 8 depending on your altitude according to the table below.

WARNING

DO NOT adjust the other dip switches unless specifically instructed to do so. Incorrect Dip Switch Settings can cause the water heater to operate in an unsafe condition and may damage the water heater and void the warranty.

H2

OVERHEAT

H1

GND

SWITCH

MODULATING

H3

P

(CN3) D

D3

1

SOLENOID VALVE

POV

FROST SENSING

P

BL

FLAME ROD

Y

BR

SWITCH

H4

H5

3

BL BL

D5

MAIN SOLENOID VALVE

SV0

P

(W) (W)

BK

ANTI-FROST HEATER

H6

SURGE

W

SOLENOID VALVE 1

SV1

Y

W

BK

PROTECTOR

D2

H7

BL

1

BK

BLBL

D4

SOLENOID VALVE 2

SV2

BL

3

BK

BR 3

1

W

FUSE

ANTI-FROST HEATER

H8

G/Y

D1

G/Y

(3A)

SOLENOID VALVE 3

SV3

BR

BK

AC120V

GND

GND

W BK

HOT

NEUTRAL

GROUND

SW					NOTES
No.
2		Off	Level 0	Off	Level 1	On	Level 2	On	Level 3
	High Altitude		0-2000ft		2001-5200ft		5201-7700ft		7701-10200ft
3		Off		On		Off		On
			(0-610m)		(610-1585m)		(1585-2347m)		(2347-3109m)

070 00012 39526 5

505 Outdoor

305

U287-1185 (02)