VIII) COMBINATION POTABLE WATER HEATING AND SPACE HEATING (COMBO HEATING)
This section serves as a guide for the installation and use of “Combo” heating systems utilizing a domestic water heater which has been specifically approved for such use. It is written for those knowledgeable in the required trades and professionals involved in the design and installation of Combo Heating Systems.
It is the responsibility of the installer/ designer to follow all applicable codes to ensure the effectiveness and safety of the installation.
Caution: 
READ BEFORE PROCEEDING
The following requirements must be met for the installation of Combo Heating Systems:
1.All components used for the distribution of water in the heating loop must be suitable for potable water. These include all piping, fittings, solder and fluxes, pumps for circulation of water, valves, etc.
2.The water heater must not be connected to a
hydronic heating system that has been used previously.
3.No boiler treatment chemicals of any kind shall be introduced into the system.
4.The Combo System components must be selected and sized to meet and maintain the total calculated demands for both domestic service hot water and
space heating requirement. The sizing and installation must be performed in accordance with good engineering practice such as ASHRAE Handbooks, HRAI, Hydronics Institute Manuals, CGA B149, NFPA 54, ANSI Z223.1, CSA F280, National/Provincial Building Codes, CSA C22.1, ANSI/NFPA 70, CSA B51 and/or codes having jurisdiction.
5.The air handler (fan coil) and/or the circulating pump in a baseboard hydronic loop will require a dedicated 120V circuit. This must be provided and identified for this purpose.
6.All piping between the water heater and the air handler or hydronic baseboard loop must be adequately insulated to reduce heat loss.
7.If local jurisdiction require a
8.To reduce the scald hazard potential, a mixing valve must be installed.
INSTALLATION
The installation of the water heater must follow sections I to X in this manual. The heating mode may be one of the following options:
A- A fan coil (air handler)
B- A hydronic baseboard (finned tube) loop/ In floor heating
A- Fan Coil (see figure 13)
The following is a list of requirements for the installation of the heating loop to the water heater.
1)Install
2)Install a drain valve at the lowest point of the heating loop so that water can be drained from the heating module without affecting the water heater.
3)If the air handler does not have a venting means at the highest point of the piping arrangement, install an air bleed at the highest point of the plumbing arrangement.
B- Baseboard Radiator Heating (see figure 13)
The following is a list of requirements for the installation of the heating loop to the water heater.
1)Install
2)A drain valve must be installed at the lowest point of the heating loop so that water can be drained from the heating module without affecting the water heater.
