Honeywell L641 Surface Contact Thermostat Instructions
L641 SURFACE CONTACT THERMOSTAT
APPLICATION
High Limit
Underfloor
Heating
Systems (see
note 2)
Low Limit
Frost
Protection
(see note 3)
DHW Storage
Tanks/
Cylinders
(see note 1)
High Limit
Solid Fuel
Systems (see
note 2)
Fan-Coil Unit
Summer/
Winter
Changeover
for 2-pipe
units (see
note 4)
L641Al039
L641Bl004
L641Bl012
Notes
1.
2.
3.
4.
The L641A should be mounted 1/4 to 1/3 of the way from the bottom of the cylinder.
The L641B should be mounted less than 0.6 m (2') from the boiler.
The L641B should be mounted on the boiler return pipe and used in conjunction with the T4360A FrostStat.
The L641B should be set to approx. 25o C and mounted on the supply pipe close to the 3-port control valve
such as to sense the water temperature even when the valve is closed.
Water Temperature Sensing and Control
D.H.W. Storage Cylinders
and Tanks
Limit Control in Pipes
High Limit
For Underfloor Heating
For Solid Fuel Systems
Low Limit
For Frost Protection of
Exposed Pipework
L641A1039
T4360A FrostStat
3
l641-en0r8444-uk07r0515
| General | Details |
|---|---|
| Name | Honeywell L641 Surface Contact Thermostat Instructions |
| Make | Honeywell |
| Language | English |
| Filetype | PDF (Download) |
| File size | 0.15 MB |

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