Olsen HTL-90D, Installation, Operation & Maintenance Manual

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OIl buRNeRs

The thermostat should be located approximately 5 feet above the 

floor, on an inside wall where there is good natural air circulation, 

and where the thermostat will be exposed to average room tempera-

tures. Avoid locations where the thermostat will be exposed to cold 

drafts, heat from nearby lamps and appliances, exposure to sunlight, 

heat from inside wall stacks, etc.
The thermostat heat anticipator should be adjusted to the amper-

age draw of the heating control circuit as measured at the "R" and 

"W" terminals of the thermostat. To reduce the risk of damaging the 

heat anticipator, do not measure this current with the thermostat 

connected to the circuit. Measure the amperage by connecting an 

ammeter between the two wires that will connect to the thermostat 

"R" and "W" terminals.

humidifier

A humidifier is an optional accessory available through most heating 

supply outlets. Installation should be carried out in accordance with 

the humidifier manufacturer's installation instructions. Water or 

water droplets from the humidifier should not be allowed to come 

into contact with the furnace heat exchanger. Do not use direct drive 

motor connections as a source of power for 120 VAC humidifiers 

and humidifier transformers.

Piping Installation

The entire fuel system should be installed in accordance with the 

requirement of CAN/CSA B-139, and local regulations. Use only ap-

proved fuel oil tanks, piping, fittings and oil filter.
In the United States the installation must be in accordance with 

NFPA No. 31 and local codes and authorities.
Install the oil filter as close to the burner as possible. For further 

details of the oil supply tank and piping requirements, please refer 

to the instructions and illustrations in the oil burner and oil pump 

instructions shipped with the furnace.

Oil filter

All fuel systems should include an oil filter between the fuel oil stor-

age tank and the oil burner. When using an oil burner nozzle smaller 

than 0.65 U.S. Gallons Per Hour, install an additional 7 to 10 micron 

filter as close as possible to the oil burner.

Oil burner Nozzles

The HTL-D and HTLV-D are certified for multiple firing rates, rang-

ing from 89,000 to 140,000 Btu/h. By manipulating the oil burner 

nozzle, flame retention head, static plate and temperature rise; the 

furnace may be fired at an ideal rate for a wide range of structures. 

Refer to Tables 3A, B and C, 

page 11 and the furnace rating plate 

to determine the proper combinations.

Oil burner Adjustment

The burner air supply is adjusted to maintain the fuel to air ratio 

to obtain ideal combustion conditions. A lack of air causes "soft" 

and "sooty" flames, resulting in soot build-up throughout the heat 

exchanger passages. Excess combustion air causes a bright roaring 

fire and high stack temperatures resulting in poor fuel efficiency. The 

HTL-D and HTLV-D furnaces operate most efficiently with a No. 1 

smoke spot on the Bacharach Scale. This is not necessarily the opti-

mum setting; however, because dust will inevitably build up on the 

air moving components of the oil burner assembly. This will result 

in decreased air supply with the potential result of soot building up 

in the flue gas passageways of the heat exchanger. Soot behaves as an 

insulator and impairs good heat transfer. Stack temperature will in-

crease, and the overall efficiency will decrease. As a means of avoid-

ing this problem, it is advisable to adjust the air supply to provide no 

more than a trace smoke spot on the Bacharach Scale.

!

CAUTION

BEFORE OPERATING THE FURNACE CHECK BURN-

ER ALIGNMENT WITH COMBUSTION CHAMBER. 

THE END CONE OF THE AIR TUBE MUST BE CEN-

TRED TO THE ACCOMMODATING RING PROVIDED 

IN THE DESIGN OF THE COMBUSTION CHAMBER. 

ADJUST AS NECESSARY.

burner electrodes

Correct positioning of the electrode tips with respect to each other, 

to the fuel oil nozzle, and to the rest of the burner is essential for 

smooth light ups and proper operation. Refer to the oil burner in-

structions shipped with the furnace for electrode specifications.

NOTICE

Beckett AF Series Burner electrode specifications have 

been revised. They should be adjusted to be 5/16” above 

the nozzle centerline.

burner Primary (safety) control

The furnace is equipped with a primary combustion control, some-

times referred to as the burner relay or burner protector relay, which 

uses a light sensing device (cad cell) located in the burner housing, 

to monitor and control combustion. Over time, dust or combus-

tion residuals can build up on the lens of the cad cell impairing its 

response to the flame. The cad cell should be checked for cleanliness 

and proper alignment if the primary control frequently shuts down 

combustion.