Honeywell 2450CMG User Manual

INDUSTRIAL APPLICATIONS Application Note

2450CMG Series Ceramic Manual Reset Commercial
Thermostats in Water Heater/Boiler Flame Rollout Control
Applications

BACKGROUND

Insufficient or contaminated air in a water heater/boiler’s
combustion system may cause a buildup of pressure, causing
a flame rollout, where a flame actually comes out of the
appliance. Flame rollout can create a serious fire hazard if
flammable materials are stored near the applicance.

SOLUTION

The 2450CMG Series Ceramic Manual Reset Commercial
Thermostat (see Table 1) is designed to detect initial flame
enlargment in the hot water heater/boiler and prevent its
reoccurance. If flame enlargement occurs, the thermostat
opens, cutting the electrical supply to the water heater/boiler,
which then cuts the fuel supply to the burner/heat exchanger
(see Figure 1).

Table 1. 2450CMG Series Ceramic Manual Reset Commercial Thermostat

2450CMG Series

Figure 1. 2450CMG Series in Flame Rollout Control in
Commercial Water Heater/Boilers

A 2450CMG Series Thermostat
B Brass extender
C Flame

D Pilot tube
E Control

Features and Benefits

• High temperature, ceramic manual reset thermostat withstands exposure temperatures up to 260 °C [500 °F]

• Configurable operating point may be tailored to application requirements up to 232° C [450 °F]

• WE-1 gold alloy cross point contacts designed for potential low voltage/low current applications

• Preset temperature and tamper proof provides temperature accuracy within the preset temperature/tolerances

• UL, CSA and VDE approved for use in global applications

• Variety of mounting studs, brackets and terminals for application flexibility

Sensing and Control

2450CMG Series in Flame Roll Out Control Application

WARNING

PERSONAL INJURY

DO NOT USE these products as safety or emergency stop

devices or in any other application where failure of the

product could result in personal injury.

Failure to comply with these instructions could result in

death or serious injury.

WARRANTY/REMEDY

Honeywell warrants goods of its manufacture as being free of
defective materials and faulty workmanship. Honeywell’s
standard product warranty applies unless agreed to otherwise
by Honeywell in writing; please refer to your order
acknowledgement or consult your local sales office for specific
warranty details. If warranted goods are returned to Honeywell
during the period of coverage, Honeywell will repair or replace,
at its option, without charge those items it finds defective. The
foregoing is buyer’s sole remedy and is in lieu of all other
warranties, expressed or implied, including those of
merchantability and fitness for a particular purpose. In no event
shall Honeywell be liable for consequential, special, or indirect
damages.

WARNING

MISUSE OF DOCUMENTATION

• The information presented in this application note is for

reference only. Do not use this document as a product

installation guide.

• Complete installation, operation, and maintenance

information is provided in the instructions supplied with

each product.

Failure to comply with these instructions could result in

death or serious injury.

SALES AND SERVICE

Honeywell serves its customers through a worldwide network
of sales offices, representatives and distributors. For
application assistance, current specifications, pricing or name
of the nearest Authorized Distributor, contact your local sales
office or:

E-mail: [e-mail]

Internet: www.honeywell.com/sensing

While we provide application assistance personally, through
our literature and the Honeywell web site, it is up to the
customer to determine the suitability of the product in the
application.
Specifications may change without notice. The information we
supply is believed to be accurate and reliable as of this printing.
However, we assume no responsibility for its use.

Phone and Fax:

Asia Pacific [phone]

[phone] Fax

Europe [phone]

[phone] Fax

Latin America [phone]

[phone] Fax

USA/Canada [phone]

[phone]

[phone] Fax

Sensing and Control

Honeywell

1985 Douglas Drive North

Golden Valley, MN 55422

www.honeywell.com/sensing

008044-1-EN IL50 GLO Printed in USA
March 2009
Copyright © 2009 Honeywell International Inc. All rights reserved.