Operating instructions

Part number 550-141-887/0800
16
AHE Series 4 Direct Vent Wall-Mounted Boilers — Boiler Manual
4b Water piping — low temp systems
Figure 13 Low temp boiler-bypass piping
Low water temperature boiler-
bypass piping
1. Do not use conventional bypass piping on radiant
panel systems or systems requiring water
temperature lower than boiler temperature. For
these systems, follow piping diagram shown in
Figure 13.
2. Adjust valves to maintain system supply and return
at design temperature.
Water treatment
See WARNING on page 3 for important information
regarding boiler water.
For unusually hard water areas or low pH water
conditions (below 7.0) consult local water treatment
company.
Freeze protection
See WARNING on page 3 for important information
regarding glycol hazard.
Do not use ethylene glycol,
automotive or undiluted antifreeze.
Severe personal injury or death can
result.
4a Water piping — general information con’t
1. Determine antifreeze quantity according to system
water content. Boiler water content is listed on page
47.
2. Follow antifreeze manufacturer’s instructions.
3. A 50% solution of propylene glycol/water provides
maximum protection to about -30 °F. Do no exceed
50% solution.
4. Local codes may require a back flow preventer or
actual disconnect from city water supply.
5. When using antifreeze in a system with automatic
fill, install a water meter to monitor water makeup.
Glycol will leak before the water begins to leak,
causing glycol level to drop. Added water will dilute
the antifreeze, reducing the freeze protection level.
To system From system
Thermometer
Balancing valve
Boiler
Supply
Return
Auxiliary pump
88713