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LAARS Mighty Therm2 MT2V (Sizes 200, 300, 400) - Install and Operating Manual User Manual

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LAARS Heating Systems

Page 16

NOTE: The Mighty Therm2 appliance and all other

gas appliances sharing the gas supply line must

be firing at maximum capacity to properly measure

the inlet supply pressure. The pressure can be

measured at the supply pressure port on the gas

valve. Low gas pressure could be an indication of

an undersized gas meter, undersized gas supply

lines and/or an obstructed gas supply line.

SECTION 4A.

Water Connections —

Mighty Therm2 Boiler

4A.1 Heating System Piping:

Hot Supply Connections — Boiler

NOTE: This appliance must be installed in a closed

pressure system with a minimum of 12 psig (82.7

kPa) static pressure at the boiler.

Hot water piping should be supported by suitable

hangers or floor stands. Do not support piping with

this appliance. Due to expansion and contraction of

copper pipe, consideration should be given to the type

of hangers used. Rigid hangers may transmit noise

through the system resulting from the piping sliding in

the hangers. It is recommended that padding be used

when rigid hangers are installed. Maintain 1" clearance

to combustibles for hot water pipes.

Pipe the discharge of the relief valve (full size)

to a drain or in a manner to prevent injury in the event

of pressure relief. Install an air purger, an air vent,

a diaphragm-type expansion tank, and a hydronic

flow check in the system supply loop. Minimum fill

pressure must be 12 psig (82.7 kPa). Install shutoff

valves where required by code.

Suggested piping diagrams are shown in

Figures

4, 5, 6, 7 and 8.

These diagrams are meant only as a

guide. Components required by local codes must be

properly installed.

4A.2 Cold Water Make-Up — Boiler

1. Connect the cold water supply to the inlet

connection of an automatic fill valve.

2. Install a suitable back flow preventer between the

automatic fill valve and the cold water supply.

3. Install shut off valves where required.

NOTE: The boiler, when used in connection with a

refrigeration system, must be installed so the chilled

medium is piped in parallel with the boiler with

appropriate valves to prevent the chilled medium

from entering the boiler.

The boiler piping system of a hot water heating

boiler connected to heating coils located in air

handling appliances where they may be exposed to

refrigerated air circulation must be equipped with flow

control valves or other automatic means to prevent

gravity circulation of the boiler water during the

cooling cycle.

A boiler installed above radiation level, or as

required by the authority having jurisdiction, must be

provided with a low water cutoff device either as a part

of the boiler or at the time of boiler installation.

4A.3 Water Flow Requirements — Boiler

A hydronic heating (closed loop) application

recirculates the same fluid in the piping system. As a

result, no new minerals or oxygen are introduced into

the system. To ensure a proper operating temperature

leading to long boiler life, a flow rate has been

established based on the fluid temperature rise for this

specific size boiler.

Pump-mounted boilers can be ordered for use in

primary secondary piping systems. The pumps used

are sized for the head loss through the heater, plus 30

feet (9.1 m) of full-sized piping (same size as boiler

outlet) and a normal number of fittings.

Table 8

specifies water flow rates for boilers,

which will enable the user to size a pump. The head

loss shown is for the heater only, and the user will

need to add the head loss of the system piping to

properly size the pump.

The minimum inlet water temperature for the

Mighty Therm2 is 120°F (49°C) to avoid condensing

on the copper coils.

4A.4 Freeze Protection — Boiler

Boiler installations are not recommended in

areas where the danger of freezing exists unless proper

precautions are made for freeze protection. A non

toxic, heating system, anti-freeze may be added to

the hydronic system provided that the concentration

does not exceed 50% and the anti freeze contains an

anti foamant. When a 50/50 mixture is used, increase

the water flow requirements by 15%, and increase the

head loss requirements by 20%.

Power outage, interruption of gas supply, failure

of system components, activation of safety devices,

etc., may prevent a boiler from firing. Any time a

boiler is subjected to freezing conditions, and the

boiler is not able to fire, and/or the water is not able

to circulate, there is a risk of freezing in the boiler

or in the pipes in the system. When water freezes,

it expands. This can result in bursting of pipes in the

system, or damage to the boiler, which could result in

leaking or flooding conditions.

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