7.Cold incoming water connection made to wrong side of heater
Make sure cold water inlet connection is on the right side of heater when you are facing heater.
8.Water valve parts may be dirty of components damaged First check that venturi is free of dirt particles. Water valve and component parts must be totally free of dirt. In hard water areas, mineral deposits can eventually
9.Loose connection at the ECO
Ignition sparker will not operate if the electrical circuit is interrupted. Check that the connections to the ECO are secure and tighten if necessary.
SPARKS APPEAR AT PILOT WHEN HOT WATER TAP TURNED ON, BUT PILOT AND BURNERS WILL NOT IGNITE
1. Air in the Gas Line
Normally this is a problem at time of initial installation, after the pipes have been worked on, or after a gas supply line has been allowed to empty. Bleed the air trapped in the gas line by turning the hot water faucet on and off until the air has been cleared from the line.
2. No gas to the Bosch
A. Gas cock on gas line may not be open
B. Gas regulator may be shut or damaged. Replace or unjam the regulator. Note: The regulator furnished with the heater is exclusively designed for low gas pressure. Excessive pressure will lock it up. Jamming usually happens when using propane gas if the gas pressure between the gas tank and the water heater’s gas regulator has not been reduced. See Page 15 for recommended correct gas pressure. To unjam a regulator, consult your gas supplier.
3. Pilot orifice or gas valve is dirty
Clogging of the pilot burner can be caused by dust in the air or dirt in the gas. The pilot orifice or gas filter may need to be cleaned or replace.
4. Water valve assembly needs to be checked
If the pilot orifice is clean, the water valve assembly should be checked. The adjustment screw on the water valve micro- switch may not be tight enough (Fig. 13). Remove central cap beneath
5.Pilot electrovalve switch may need to be replaced (See Fig 14).
Call your service person or call: Canada
6.Electronic Control Box may need to be replaced, (See Fig 14).
Call your service person or call: Canada
PILOT SPARKS CONTINUOUSLY WITH
NO WATER RUNNING
1. Microswitch needs adjustment
If no water is running, but pilot electrode continuously sparks, the microswitch screw to the water valve needs adjustment. See Figure 13.
PILOT LIGHTS BUT BURNERS
WILL NOT COME ON
1.Confirm water valve assembly is working properly.
2.Confirm the flame sensor is in its proper position.
3.Confirm the burner electrovalve switch is functioning properly. Contact your service person or call:
Canada
4.The electrical Control Box (Fig. 14) may need to be replaced. Contact your service person or call:
Canada
1 | - microswitch | 8 - ionization probe (flame sensor) | |
2 | - circuit interrupter | ||
9 - fuse | |||
3 | - temperature limiter | ||
10 - pilot electrode | |||
4 | - sensors of exhaust gases | ||
11 - control box | |||
5 | - burner electrovalve | ||
12 - power cord | |||
6 | - pilot electrovalve | ||
13 - exhaust fan | |||
7 | - gas control valve | ||
|
Fig. 14 - Electrical wiring diagram
MAIN BURNERS GO OUT DURING HOT
WATER USE
1.Flow rate diminished below activation rate: 0.5 USGM (2.5 l) in hot position, 1.0 USGM (5 l) in warm position.
2.Unbalanced pressure in the water lines
The added restriction caused by the Bosch in the hot water system can result in uneven pressures between the cold and the hot. In such cases when mixing cold water at the tap, the lower hot water pressure may be overpowered by a much higher cold water pressure, which may cause the Bosch burners to shut down. Make sure faucet aerators and showerheads are free of minerals and dirt. Do not add any flow restrictor to the shower head.
3.Check gas supply
4.ECO (overheat sensor) tripped due to overheating
5.Minimum inlet pressure on well is inadequate
Check the inlet water pressure. On a private well, raise the minimum pressure setting to 40 psi for best performance. Confirm that the pressure tank is not water logged.
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