Install shutoff (ball) valves for servicing convenience. Install thermometers on the inlet and outlet lines.
Never plug the pressure relief valve to avoid creating a hazardous situation.
3.5.2 Flow-check valve
If the heating system uses a single circulator, a
3.5.3 Pressure relief valve
No boiler
The BTU per hour rating of the relief valve must equal or exceed the BTU per hour input of the boiler(s) or heat source(s) as marked on the boiler(s) rating plate.
Connect the outlet of the relief valve to a suitable open drain, with the discharge at most 6” above the floor, far from any live electrical parts. The discharge line must pitch downward from the valve to allow complete draining and be no smaller than the outlet of the valve. The end of the discharge line should not be threaded or concealed and should be protected from freezing. No valve of any type, restriction or reducer coupling should be installed in the discharge line. Local codes shall govern the installation of relief valves.
3.5.4Operating pressure control : expansion tank
Operating pressure control components ensure minimum and maximum operating limits are observed within the design operating temperature range. These components allow bleeding air from the piping, prevent boiling and cavitation at the circulator inlet, while minimizing the amount of fresh water input. Please contact a qualified plumber or contractor for more information on this subject.
The expansion tank connection point must be carefully chosen to prevent a situation where closing a valve would isolate the tank from the
boiler or any part of the circuit. It is preferable to use a calibrated diaphragm expansion tank.
3.5.5 Makeup valve
Connecting a makeup valve must be done according to code. This valve must include a
3.5.6 Air bleeder
There should be as little oxygen as possible in the heating circuit to prevent corrosion. As foreseen in section 3.5.4, this excludes the use of air as a pressure regulator within the circuit.
Installing manual or automatic air bleeders prevents air accumulation within the system. The bleeders must be set at the highest points of the system to purge any air accumulated during system
3.5.7 Circulator zoning
A
3.5.8 Zone valve zoning
Zone valves with low pressure drop are recommended. (see figure 3)
3.5.9Circulator selection criteria
The COMBOMAXMC boiler includes a pre- mounted circulator. The information below will help you select additional units for multiple circulator
3.5.9.1 Pump flow rate calculation
The boiler output rating must correspond to the calculated heating load. Use the equation below to calculate the pump flow rate:
COMBOMAXMC Electric boiler