16
warmhaus.com
Error
Code
Description of the
Error
Malfunction
Probable Cause
Solution(s)
E 21
Delta Temperature
Central Heating
flow and Return >
TSP 82 value °C
Boiler does not
work, E21 error
code flashing on
the screen
> Lack of water on
the system
> Pump blockage
> Pump failure
> Pump harness
> Installation
blockage
1) RESET boiler at first check if problem
removed
2) Check boiler central heating valves are
open if they are closed open all
3) Check all radiator valves are open if
they are closed. Minimum 3 meters of
radiator must be open
4) RESET boiler and check if problem
resolved
5) Call for authorised service
E 28
Maximum allowed
consecutive lock-
out reset reached
Usable RESET
number reached.
Too many
consecutive
lock-out failures
(followed by
reset) due to other
possible causes
1) Turn OFF the power of the appliance.
Reset will be allowed after turning ON the
power.
2) Check the root cause of Error to solve
3) If fault still persists call for authorised
service
E 37
Low voltage
anomaly
Boiler does not
work, E37 error
code flashing on
the screen
Low voltage < 165
VAC +/- 5%
on the supply
network during
normal operation
OR < 182 VAC +/-
5% during Au-TO
calibration mode
1) Call for Electrical supply network
provider
2) Error will remove if supply voltage > 170
VAC +/- 5%
3) If this failure is observed during
calibration calibration can not be complete
unless supply voltage > 188 VAC +/- 5%
E 40
Wrong network
frequency
survey
Boiler does not
work, E40 error
code flashing on
the screen
Wrong frequency of
the electric supply
network. Value out
of tolerance, 50 Hz
+/- 5%
1) Call for Electrical supply network
provider
2) Error will remove if supply frquency 50
Hz +/- 5%
E 41
Loss of flame more
than 6 successive
times
Boiler does not
work, E41 error
code flashing on
the screen
> Too many
domestic hot water
request in short
period ( 1 min )
> Low gas pressure
1) Call for authorised service at first
E 42
Buttons anomaly
Boiler does not
work, E42 error
code flashing on
the screen
Wrong parameters
settled on TsP
menu
1) Call For authorised service.
E 43
Opentherm
Communication
error
Boiler does not
work, E43 error
code flashing
on the screen
after 1 minute of
communication
error
Opentherm line
disconnected
1) Remove energy from boiler and re
energize E43 will be removed and boiler &
buttons will get back to funcitional
2) Replace the room unit batteries with
the fresh ones and reset from room unit
3) Check cabling between boiler and room
unit and re connect if any disconnection,
if connection set up succesfully then
connection symbol will be activated on
the screen
4) Call for authorised service to re connect
openterm connection
