Munchkin Gas-Fired Hot Water Circulating Heater Part 5 Munchkin Contender Piping

GAS-FIRED HEATER Installation Manual

PART 5: MUNCHKIN CONTENDER PIPING

A. RELIEF VALVE

Connect discharge piping to safe disposal loca- tion, following guidelines in the WARNING below.

WARNING

To avoid water damage or scalding due to relief valve operation:

•Discharge line must be connected to relief valve outlet and run to a safe place of disposal. Terminate the discharge line in a manner that will prevent possibility of severe burns or property damage should the valve discharge.

•Discharge line must be as short as possible and be the same size as the valve discharge connection throughout its entire length.

•Discharge line must pitch downward from the valve and terminate at least 6” above the floor drain where any discharge will be clearly visible.

•The discharge line shall terminate plain, not thread- ed, with a material serviceable for temperatures of 375 °F or greater.

•Do not pipe the discharge to any place where freez- ing could occur.

•No shutoff valve shall be installed between the re- lief valve and heater, or in the discharge line. Do not plug or place any obstruction in the discharge line.

•Test the operation of the valve after filling and pres- surizing system by lifting the lever. Make sure the valve discharges freely. If the valve fails to operate correctly, replace it with a new relief valve.

•For heaters installed with only a pressure relief valve, the separate storage vessel must have a tem- perature and pressure relief valve installed. This re- lief valve shall comply with the standard for Relief Valves for Hot Water Supply Systems, ANSI Z21.22 CSA4.4.

•Failure to comply with the above guidelines could result in failure of the relief valve to operate, re- sulting in possibility of severe personal injury, death or substantial property damage.

B. GENERAL PIPING INFORMATION

CAUTION

Use two wrenches when tightening water piping at heater, using one wrench to prevent the heater return line or supply line from turning. Failure to support the heater piping connections to prevent them from turning could cause damage to heater components.

NOTICE

The Munchkin Contender Heater control module uses temperature sensors to provide both high limit protection and modulating temperature control. The control module also provides low water protection by sensing the water pressure of the heat exchanger. Some codes/jurisdictions may require additional external controls for high limit and/or low water cutoff protection.

C. SEPARATE LOW WATER CUTOFF

A low water cutoff may be required by state local code or some insurance companies. Check code requirements before installation of the Munchkin Contender Heater. It is also required that a low water cutoff be used if the heater is installed above the piping level.

If required:

•Use a low water cutoff designed for hydronic installations that is an electrode probe type

•Install in a tee on the supply piping above the heater

•Follow low water cutoff manufacturer’s instructions

D. BACKFLOW PREVENTER

Use a backflow preventer specifically designed for hydronic heater installations. This valve should be installed on the cold water fill supply line per local codes. (See piping details at the end of this section.)

CAUTION

All piping methods shown in this manual use primary/secondary connection to the heater loop. This is to avoid the possibility of noise or actuator problems in zone valves because of the high-head heater circulator. For other piping methods, consult your local Heat Transfer Products representative or refer to separate Munchkin Contender piping details in this manual (Part 5).

E. SYSTEM WATER PIPING METHODS

Expansion tank and make-up water

1.Ensure expansion tank size will handle heater and system water volume and temperature. Allow 3 gallons for the heater and its piping.

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