LAARS Heat Exchanger Installation Manual

Accessories & Parts Document 4043H

A subsidiary of CorporationBRADFORD WHITE

Heating Systems Company

Heat Exchanger Replacement

Gas-Fired Hydronic Boilers, Volume Water and Pool Heaters

Sizes 175,000 - 5,000,000 BTU/hr.

To Remove Heat Exchanger:

1. Turn off all electrical power to the heater.

2. Disconnect the water piping from the header.

3. Remove the vent, draft diverter, and flue extension.

4. Remove the jacket top, which is secured with sheet metal
screws.

5. Withdraw the flue collector, which is held in place with
cement or metal
screws.

6. Remove the sheet
metal strips, if
present on your
model, across the
ends of the heater
above the headers.

7. Remove the capillary
tubing going to the
thermostat bulb and
high limit switch bulb.
If the heat exchanger
is to be reversed, the existing tubing will have to be replaced
with longer tubing.

8. On heaters equipped with a mounted pump on the side of the
jacket, remove the screws holding the bracket. Maintain the
pump, bracket, and heat exchanger as one unit. Disconnect
all electrical wiring.

9. Remove the front and rear tile covers.

Lift out the heat exchanger. It may have to be jiggled carefully

to break the furnace cement seal.

To Reinstall the Heat Exchanger:

1. Coat the upper surfaces of the side tiles with furnace cement
before carefully lowering the heat exchanger into place.

2. Verify that all of the "V" and "T" baffles are properly installed
between the heat exchanger tubes. Also, be sure end refrac­tory tiles fit inside of the casting ribs and seal on the flat part
of the casting.

3. Replace the front and rear tile covers.

4. Repeat steps 1 through 8 of the removal procedure in reverse
order to complete the installation.

Water Barrier Position

Water barrier must be installed as shown in diagrams at right or
warranty is void. The diverter plate must be reinstalled between
the tub and header cover on the inlet side of the heat exchanger.
When replacing a heat exchanger, the water barrier must
be installed to ensure a proper fit with the replacement heat
exchanger. Water barrier p/n for I/E 500-1825 and Q boilers
500-1666 is 20230101. Water barrier p/n for LB 2000-5000 is

20230100.

BARRIER

BARRIER

SPECIAL BYPASS ASSEMBLY

PUMP DISCHARGE BAFFLE

PUMP DISCHARGE BAFFLE
(in pump adapter)

BARRIER WITH HOLE

PUMP DISCHARGE BAFFLE

BARRIER

SUCTION DIFFUSER

PUMP DISCHARGE BAFFLE
(in pump adapter)

SUCTION DIFFUSER

PUMP DISCHARGE BAFFLE
(in pump adapter)

SUCTION DIFFUSER

For Models:
LC 154-3000
LJ, LL, LQ 500-4000
HK, LK 250-400
HB, LCR 154-560
VW, HH 500-1825
VW, HH 2000-5000

HB, LCR 630-3000
HJ, HL, HQ 500-4000
LJ, LL, LQ 500-4000
VW, HH 2000-5000

AF 420-3000
AL 1866-4000
AP 2200-4000
AP 2000-5000

AJ, AL, AQ 500-1666
AP 500-1825

NC 154-3000
NK 250-400

NJ, NL, NQ 500-1666
PW, PH 500-1825

SJ, SL, SQ 500-1666
IW 500-1825

SK 250-400
SC 560-3000

RB 560-1190
RJ, RL 500-1666
MJ, ML 500-1666
MK 250-400

RJ, RL, RQ 500-1666
MJ, ML, MQ 500-1666
with rear mounted pump

H0062400H

800.900.9276 • Fax [phone] (Customer Service, Service Advisors)

20 Industrial Way, Rochester, NH 03867 • 603.335.6300 • Fax [phone]
1869 Sismet Road, Mississauga, Ontario, Canada L4W 1W8 • 905.238.0100 • Fax [phone]

www.Laars.com Litho in U.S.A. © Laars Heating Systems 0806 Document 4043H