Lochinvar F0600187510 Adjusting Differential Air Pressure, Combustion Air Fans, Fan Cleaning

Installation and Service Manual

Combustion Air Fans

Both the 500,000 - 750,000 Btu/hr models and the 990,000 - 2,070,000 Btu/hr models use a fan-assisted combustion process. The 500,000 - 750,000 Btu/hr models have one fan

and the 990,000 - 2,070,000 Btu/hr models use two fans to supply combustion air to the burners.

Fan Cleaning

Check each combustion air fan every six months. Clean the fan as required when installed in a dusty or dirty location. Oiling is not required.

Combustion Air Fan Adjustment

The combustion air fans are factory pre-set and should not need adjustment in most cases. Follow the steps below to adjust the fan

if a continuous Low Air status code occurs.

Figure 53 – Loosening Fan Transition Box Screws

Note: On the 500,000 - 750,000 Btu/hr models the air shutter is adjusted on the side of the fan duct as depicted in Figure 52. On the 990,000 - 2,070,000 Btu/hr models the air shutter is adjusted on the rear of the fan duct as depicted in Figure 54.

1. Check for proper installation and draft in the venting system. Correct as required.

2. The following pressure settings are for installations up to 4000 feet altitude. Contact the factory for high altitude air pressure settings.

Adjusting Differential Air Pressure

The following is a recommended method for setting the differential air pressure (ΔP) for each fan.

LESS AIR

EAIR

R

O

M

AIR SHUTTER

Figure 52 – Adjusting Air Shutter 500,000 - 750,000 Btu/hr

Figure 54 – Adjusting Air Shutter 990,000 - 2,070,000 Btu/hr Models

Set-Up Procedure

Beside the fan duct is an air pressure switch with a large and a small tube delivering pressure from points inside the pool heater (see Figure 55). The pressure in the large tube is the chamber pressure. The pressure in the small tube is the burner pressure. They act together to make the pressure switch. By disconnecting the caps from the tees in the pressure switch hoses and connecting them to either side of a manometer, you can read the differential pressure to the switch.

The left pressure tapping connection on the manometer connects to the tee in the tubing from the pool heater front chamber and the right pressure tapping connection on the manometer connects to the tee in the small tubing from the burner.

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