Pentair MT warranty Troubleshooting and Analysis Service Problems, Possible Cause What To Do

Boiler Will Not Fire

Possible Cause

What To Do

Electric Power

Check to see that main power switch

is off.

is ON. Use testing device to trace

power to boiler junction box.

Operating or

Turn off power. Use continuity tester

safety control has

to check continuity across terminals of

opened circuit to

each operating and safety control

electric gas valve.

switch up to the electric gas valve.

Replace defective control.

Pilot flame is out.

Relight pilot per instructions.

Manual reset

Follow instructions for start-up. Reset

device has

pilot safety and all manual reset

tripped.

safety switches.

No gas pressure to

Trace gas line to service shutoff cock.

burners.

If service cock is open, trace gas line

to meter. If no pressure is present at

meter, call for public utility service. If

gas is present in heater inlet, check

pressures in following sequence:

(1) downstream from pressure

regulator,

(2) downstream from electric gas

valve. Replace or adjust as

necessary.

Electric gas valve

Disconnect wiring harness at gas

operator is burned

valve terminals. Check continuity to

out or shortened.

actuator coil. If open circuit or short is

indicated, replace coil or operator.

Possible Cause

What To Do

Lower or no water

This condition is usually caused by

flow.

lack of adequate water flow through

heater. check the following:

1. Is the heater wired into the pump

circuit so that the heater cannot fire

unless the pump is running?

2. Check to see that all valves in

system are open to be sure that water

can circulate through the heater and

the system.

3. Examine pump for clogged

impeller.

4. Check water filter.

Debris from system

Remove header covers. Examine all

is blocking tubes.

tubes and waterways. Use new

gaskets when reassembling. Clean

out tubes.

Scale has formed

This is always caused by heavy

in tubes.

mineral content of the water or

clogged filter. Check the water

chemistry. Replace the filter and

clean all the internal wet surfaces.

Possible Cause

What To Do

Combustion air

Check air supply opening. Look for

supply to

debris in screen or louvre which

equipment room is

covers combustion air opening, or for

inadequate.

material blocking the opening.

Stack or vent is

Look for blocked stack and excessive

blocked or

number of elbows in stack or

restrictive.

excessive length of horizontal runs.

Severe down draft

Check for (1) proper vent cap on

is causing spillage

stack; (2) adequate height of stack

of flue products

above roof; (3) equipment exhausting

into room.

air from inside of building.

Gas pressure to

Check gas pressure with

burners is

manometer,and adjust with heater

excessive.

firing at full rate.

Heater not fitted

See nameplate for correct fuel.

for the fuel being

supplied.

Heater installed at

Installations at altitudes in excess of

high altitude

2000 ft. above sea level are subject

without proper

to jurisdiction of the local inspection

derating.

authorities. Check with the factory.

Water Dripping in Firebox

Possible Cause

What To Do

Tube in heat

A tube failure is almost always

exchanger has

caused by:

overheated and

(a) Scale formation in the tube, or:

ruptured.

(b) inadequate water flow through the

boiler.

Replace heat exchanger tube(s) and

check for proper flow.