Lochinvar 000 - 500 User Manual

A hot water boiler installed above radiation level must be
provided with a low water cutoff device either as part of
the unit or installed at the time the boiler is installed.  An
electronic low water cutoff is available as a kit on all
units.  Low water cutoffs should be in spect ed every six
months, including flushing of float types.

The 45,000 thru 500,000 Btu/hr boilers (M9) are
equipped with a two stage burner control system.  The
45,000 thru 399,999 Btu/hr models will be equipped
with a two stage gas valve to control high/low burner
op 

er 

a 

tion.  The 500,000 Btu/hr mod 

el achieves two

stage burner firing by staging the operation of the two
combination gas valves.

This appliance is wired for 120 VAC service.  The
appliance, when installed, must be electrically
ground ed in accordance with the requirements of the
authority having jurisdiction or in the absence of such
re 

quire 

ments, with the latest edition of the National

Electrical Code ANSI/NFPA No. 70.  When the unit is
in stalled in Canada, it must conform to the CSA C22.1,
Ca na di an Electrical Code, Part 1 and/or local Electrical
Codes.

1.    All wiring between the appliance and field

in stalled devices shall be made with type T wire 
[63° F(35° C) rise].

2.     Line voltage wire exterior to the appliance must be

enclosed in approved conduit or approved metal
clad cable.

3.   The pump must run continuously when the

appliance is being fired.

4.    To avoid serious damage, DO NOT en er gize the

5.    Provide the unit with proper overload protection.

6.    Install a wall thermostat on the inside wall.  DO

NOT install the thermostat in an area affected by
drafts, sunlight, light fixtures, hot or cold water
pipes or near a fireplace.  See “Terminal  Strip Con -
nec tion of a Room Thermostat”, page 38 for prop er
wiring  con nec tion.

Pump Wiring for a Heating Boiler
The heating boiler circulating pump must be pur chased
locally.  The max i mum load for the pump switched by
the internal pump relay must not exceed 1 HP.  The
current draw for a field installed 120 VAC pump MUST
be add ed to the boiler’s current draw to de ter mine the
minimum wire size for 120 volt service.

Pipe Size                      GPM Flow Rate

1 1/2"                        

13

2"                            

18

F1 Standing Pilot (Single Stage
90,000 - 260,000 Btu/hr)

2.5

F9 Intermittent Pilot (Single Stage 
90,000 - 399,999 Btu/hr)

2.5

F9 Intermittent Pilot (Single 
Stage/2 valves 500,000 Btu/hr)

2.5

M9 with Internal Pump 
(45,000 - 260,000 Btu/hr)

2.0

M9 Intermittent Pilot (Two Stage 
Valve 315,000 - 399,999 Btu/hr)

2.0

M9 Intermittent Pilot (Two Stage/2 
valves 500,000 Btu/hr)

2.0