Weil-McLain SVF 1500 Manual page 100

SVF
™
Series 1
Commercial Condensing Gas-Fired Water Boiler — Boiler Manual
Troubleshooting
Check the following:
1. Space heating:
a. Make sure thermostat is calling for heat and contacts (in-
cluding appropriate zone controls) are closed.
b. Check for 24VAC between thermostat wire nuts and
ground.
2. DHW:
a. Make sure tank aquastat is calling for heat.
3. BMS systems:
a. Make sure the BMS is calling for heat.
4. Make sure all external limit controls are either installed (and
closed) or temporarily jumpered for testing.
5. Make sure that connectors to the control module are securely
plugged in at module and originating controls and harness
connectors.
6. Gas pressure must be as specified on page 47. Make sure gas
pressure switches are not tripped.
Always check Control module fuses
ALWAYS check control module fuses before replacing
control module or any major components (blower,
etc.). If one of these fuses is blown, it can prevent
control module or other components from operating.
1. Turn OFF power to boiler at external line switch.
2. Access the control box:
a. Remove the top front slate-colored panel.
b. Slide the glossy black panel up into its alternate position.
c. Remove the two (2) screws securing the middle slate-
colored panel and remove the panel.
d. Remove the three (3) screws securing the control box cover.
Control module fuses
1. Remove and inspect the two (2) Control fuses and the Expan-
sion module fuse (located as shown below).
2. If necessary, replace the fuse:
a. Item 1 – Low voltage circuit fuse is a 3-amp fast-blow.
b. Item 2 – Line voltage circuit fuse is a 12-amp fast-blow.
Figure 96 Control module fuse
Figure 97
Expansion module fuse
100
(continued)
Circulator and Blower Fuse
1. Remove and inspect the BOILER CIRCULATOR fuses and the
2. If necessary, replace the fuse:
a. Item 3 (tan)– Line voltage circuit fuse is a 16-amp slow-blow.
b. Item 4 (black)– Line voltage circuit fuse is a 20-amp slow-blow.
c. Item 5 (black,red & blue)– Line voltage circuit fuse is a 12.5-
Figure 98
Figure 99
1
2
3. Re-install jacket panels:
a. Re-install the control box cover and tighten the three (3)
b. Re-install the middle slate-colored panel and tighten the two
c. Slide the glossy black panel down into position.
d. Re-install the top slate-colored panel.
4. Restore power to boiler at external line switch and verify boiler
operation after completing boiler service.
Checking temperature sensors
1. The boiler temperature sensors (flue, outdoor, boiler in, boiler out,
return and system) are all resistance-type devices.
2. Figure 100, page 101 shows the correct value for the sensor at vari-
ous temperatures.
1
3. Use the resistance values at 32°F, 60°F, 70°F and 212°F to measure
the sensor resistance at known temperatures (freezing point, room
temperature and sea level boiling point). For freezing point and
Do not jumper fuse or replace with any fuse except as
specified. Failure to comply could result in severe per-
sonal injury, death or substantial property damage.
BLOWER fuse (located as shown below).
amp slow-blow.
SVF 1500/2000 Circulator and blower fuse location
3
SVF 2500/3000 Circulator and blower fuse location
3 5
screws to secure the panel.
(2) screws to secure the panel.
4
5 5
Part number 550-100-250/0819