20.2 Troubleshooting „INSUFFICENT
HEAT“ call
A call for insufficient heat is generally a simple matter of
adjusting the heating curve.
The water temperature required for any heating system
is determined by any number of factors but the biggest
influence we see is the amount of radiation in
comparison to the actual heat loss. Buildings with less
radiation in relation to there actual heat loss require
higher water temperature than buildings that are over-
radiated. Every house is unique in terms of it’s heat
requirements. Some of the many factors include,
construction, exposure to sun, elevation, surroundings
(trees, other structures, etc), furnishings, internal heat
gain (computers, lights, people, appliances, etc) and the
expectations and comfort level of the individual.
The heating curve on a R2107 can be adjusted in
several ways:
REF TEMP – the reference temperature adjusts the
slope of the heating curve. The REF temperature in the
R2107 references a boiler water temperature at 14°F
outdoor temperature. In general, if the homeowner
complains that they can never get the house up to
temperature, adjust the REF temperature up. A rule of
thumb would be: for every 1 degree you want to raise the
room temperature, increase the REF temp by 2.5
degrees.
For example: Customer says they can’t get the house
above 65°F. We need to increase the room temperature
by 5°F…5 x 2.5 = 12.5.
You would increase the REF temperature by 12 or 13
degrees. The default setting in the R2107 is 167° REF
temperature.
OFFSET – the OFFSET setting is used to raise the
starting water temperature of the system. Another way
to say this is, raising the OFFSET setting will give you
higher water temperature at milder outdoor
temperatures. Common applications for adjusting the
OFFSET setting include, hydro-air, fan coils, unit
heaters, etc. These types of heating units typically
require some amount of minimum water temperature.
Occasionally, you may have a call for insufficient heat
but only in milder weather. Even with fin-tube radiation,
cast-iron radiators or panel radiators. With this type of a
call, you will want to increase the OFFSET setting.
USE THE QUICK REFERNECE GUIDE FOR INITIAL
PROGRAMMING
Logamatic 2107 controls - We reserve the right to make any changes due to technical modifications.
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20
Troubleshooting
