503230
14
Zoom out
Zoom in
Previous page
1/74
Next page
Working principle of the appliance
14 Instruction manual BFM
2
gis
2.4 Protection for the
appliance
2.4.1 Introduction
The burner control monitors the water temperature by means of thermostats,
and ensures that the combustion is safe. This takes place using:
the Water temperature protection;
the Flame probe
;
the Pressure switch
.
2.4.2 Water temperature protection
By means of the frost, high-limit and safety thermostats, the burner control
monitors three temperatures that are important for safety. The table explains the
working principle of the thermostats with sensors.
Temperature protection
2.4.3 Pressure switch
The pressure switch ensures the discharge of flue gases and the supply of
incoming air during the pre-purge and normal running of the appliance. The
default state of the pressure switch is open. When sufficient pressure difference
is reached, the pressure switch closes. However, in the event of a fault, the
pressure switch is tripped open, and the heating cycle is interrupted. The table
shows the trip point per appliance.
Note
The trip point of the pressure switch is not adjustable.
Pressure switch trip points
Protection Description
Frost thermostat When the frost thermostat sensor (46) measures a temperature of 20 °C or
less, the heating cycle (2.3 "
The appliance's heating cycle") will start.
High-limit thermostat When the high-limit thermostat sensor (39) measures a temperature higher
than 84 °C, the high-limit thermostat will open. The heat demand is terminated
and the burner control halts the heating cycle until the high-limit thermostats
close once more. At that moment the burner control will reset the appliance and
the heating cycle will restart. The high-limit safeguard serves to prevent
overheating and/or excessive formation of scale in the appliance.
Safety thermostat When the safety thermostat sensor (38) measures a temperature higher than
93 °C, the safety thermostat will open. The heat demand is terminated and the
burner control will immediately halt the heating cycle. The burner control will go
into a lockout error state. This must be manually reset before the appliance can
resume operation.
Appliance Closing pressure
difference
Opening pressure difference
BFM 30 > 200 Pa < 170 Pa
BFM 50 > 270 Pa < 240 Pa
BFM 80 > 255 Pa < 225 Pa
BFM 100 > 610 Pa < 580 Pa
BFM 120 > 220 Pa < 190 Pa
14


Need help? Post your question in this forum.

Forumrules


Report abuse

Libble takes abuse of its services very seriously. We're committed to dealing with such abuse according to the laws in your country of residence. When you submit a report, we'll investigate it and take the appropriate action. We'll get back to you only if we require additional details or have more information to share.

Product:

For example, Anti-Semitic content, racist content, or material that could result in a violent physical act.

For example, a credit card number, a personal identification number, or an unlisted home address. Note that email addresses and full names are not considered private information.

Forumrules

To achieve meaningful questions, we apply the following rules:

Register

Register getting emails for A.O. Smith BFM100 at:


You will receive an email to register for one or both of the options.


Get your user manual by e-mail

Enter your email address to receive the manual of A.O. Smith BFM100 in the language / languages: English as an attachment in your email.

The manual is 1,88 mb in size.

 

You will receive the manual in your email within minutes. If you have not received an email, then probably have entered the wrong email address or your mailbox is too full. In addition, it may be that your ISP may have a maximum size for emails to receive.

Others manual(s) of A.O. Smith BFM100

A.O. Smith BFM100 User Manual - German - 70 pages

A.O. Smith BFM100 User Manual - Dutch - 70 pages


The manual is sent by email. Check your email

If you have not received an email with the manual within fifteen minutes, it may be that you have a entered a wrong email address or that your ISP has set a maximum size to receive email that is smaller than the size of the manual.

The email address you have provided is not correct.

Please check the email address and correct it.

Your question is posted on this page

Would you like to receive an email when new answers and questions are posted? Please enter your email address.



Info