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Logamatic 2107 Controls
Applications Manual
Logamatic 2107 Controls applications manual | 06.2018
Technical specifi cations are subject to change without prior notice
6 Troubleshooting
6.1 "NO HEAT" call
ZM1
LT GRY
“BRENNER” (burner) wiring block
– Terminal 4 – 120V Neutral
– Terminal 8 – 120V input clocks hours run meter
(must be fi eld wired)
– Terminal 9 – 120V input displays “BURNER ERR”
message (must be fi eld wired)
– Terminal 10 / 11 – “dry” contacts close to energize
burner
– Terminal 12 – 120V power (drops out when manual
reset limit is tripped)
Burner operation
The R2107 is not a cold start control. It does not reply on a call
for heat from an end switch or thermostat to fi re the boiler.
The boiler will maintain a range of water temperature based on
outdoor temperature. The diff erential of this range is dynamic,
meaning that it is not fi xed, and will adjust based on outdoor
temperature and current system load. The starting point of the
diff erential is 27°F (15°C) and will adjust from there. The
diff erential will generally be wider at milder outdoor
temperatures and narrower at colder outdoor temperatures.
The diff erential is split above & below the current target
temperature.
Example: Outdoor temperature at 32°F, based on heating curve
the water temperature required is 140°F with a 26°F burner
diff erential.
The diff erential (26°F) is split (13°F) above & (13°F)
below the target temperature.
140°F target + 13°F = 153° high limit
140°F target - 13°F = 127° low limit
This 127°F to 153°F becomes the range of temperature that the
boiler will maintain. As zones call and pull heat from the boiler,
eventually the temperature in the boiler drops. Once the
temperature in the boiler hits the low limit (127°F) the R2107
control closes a switch (dry contacts) between terminals 10 & 11
to fi re the boiler (this is indicated by a fl ame symbol displayed
on the LDC screen of the R2107). When the boiler temperature
reaches the high limit (153°F), the contacts open and the boiler
stops fi ring.
Once the outdoor temperature drops below the WWSD setting,
the boiler begins to maintain temperature. Above WWSD the
boiler will only fi re on a call for DHW.
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