Service manual

SC Series Boilers – User’s Information Manual

Figure 1 – Condensate trap

6 AIR SUPPLY FOR COMBUSTION AND VENTILATION

A sufficient air supply MUST be provided to this boiler. Air openings to the boiler room provide the air for

combustion, flue gas dilution and ventilation and are always required, regardless whether the air is taken

from inside or outside. The air opening size and location, as well as exhaust venting considerations must

conform to the applicable codes. If any alteration of the air supply and venting system is required, contact

a qualified service agency.

The boiler room must never be under a negative pressure. Air openings should be sized by your installer

not only to the dimensions required for the total input of all fuel-fired appliances in the boiler space, but

also to handle the air movement rate of any exhaust fans or air movers using air from the building or

space.

Make sure the venting terminations are always kept clear of obstructions (i.e. snow, ice, etc.). Louvers

and grilles used in your air supply and ventilation system should be checked regularly and cleaned of any

dust, dirt, or debris which will block proper air flow.

7 CHECK CONDENSATE TUBE

All boiler with vertical venting installations require a condensate drain and drain trap. Do not operate the

boiler without installing this trap and filling with water.

The condensate drain should be installed as close to the boiler as possible and must be equipped with a

drain trap. The drain tap should be formed by attaching 3/8” I.D. high temperature tubing, such as

silicone, to the drain assembly, making a loop of approximately 4” diameter and securing it with a cord or

tie wrap where the tube crosses over itself. Do not squash the tube or over-tighten it, see Figure 1. The

loop must then be filled with water to form a liquid-filled trap. This trap allows condensate to drain while

preventing exhaust gases from escaping.

Periodic inspection and cleaning should be made of this assembly.

Check for deterioration of the tubing and to ensure that the trap is filled

with water. If the tube is plugged or appears to have excessive

sediment in it, it should be removed from the condensate drain pipe,

straightened out to clear the obstruction, reformed, filled with water and

reinstalled as before. The drain should extend to a floor drain,

condensate pump or to a plastic container which may require emptying

periodically. Condensate disposal must be acceptable to the authority

having jurisdiction.

8 CHECK VENTING SYSTEM

Flue gas condensate can freeze on the exterior walls or on the vent cap.

Frozen condensate on the vent cap can result in a blocked flue condition. Some discoloration to exterior

building surfaces can be expected.

For proper operation, the vent terminal or air inlet must be kept free of snow, leaf dropping and other

debris at all times to ensure that no blockage occurs

All horizontal runs of vertical venting installation shall slope upward not less than ¼ inch per linear foot

(21 mm/m). This is to ensure that any condensate flows back towards the boiler so that the condensate

can be disposed of through the condensate disposal system installed on the venting horizontal section

closed to the boiler. Ensure that there are no sagging sections along the horizontal runs to trap water.

For a horizontal venting installation with one horizontal run. The horizontal section shall slope downward

about 1 inch from the beginning of horizontal run to the vent termination. This is to ensure that any

condensate in horizontal venting flows towards outside through the opening of termination.