User Guide

tekmar Control Systems Ltd., Canada
tekmar Control Systems, Inc., U.S.A.
Head Office: 5100 Silver Star Road
Vernon, B.C. Canada V1B 3K4
Tel. [phone] Fax. [phone]
Web Site: www.tekmarcontrols.com
Control Systems
System Operation
All specifications are subject to change without notice.
8 of 8
A 260-4 03/09
Product design, software and literature are Copyright © 2009 by:
tekmar Control Systems Ltd. and tekmar Control Systems, Inc.
Printed in Canada. A 260-4 03/09.
The Boiler Control 260 provides partial or full reset to three (or more) boiler zones. The 260 also controls the supply of heat to an indirect
fired Domestic Hot Water (DHW) tank. The boiler is operated at the required temperature in order to satisfy the loads.
Heat Source Details The heat source can be either a high mass or low mass non-condensing or low temperature boiler. If using a low
temperature boiler, refer to section C3 of the Data Brochure for additional information.
Piping Details Thermostat controlled zone pumps are piped into the boiler loop. Heat is supplied to the DHW tank through a DHW
pump (P1).
DHW Demand When the DHW aquastat (A1) calls for heat, the 260 turns on the DHW pump (P1) and raises the boiler water tempera-
ture to at least 180°F (82°C). The control can provide DHW priority (refer to section C2 of the Data Brochure) by turning off the
Boil P1
contact and not allowing any of the boiler zones to operate. Once the DHW demand is removed, the 260 performs a DHW Post Purge
and possibly a Mixing Purge .
Boiler Demand When heat is required in the boiler zones, the zone pump relays send a Boiler Demand to the 260. The boiler supply
water temperature is based on the Characterized Heating Curve settings. The boiler is fired to satisfy the required boiler supply water
temperature. Whenever the boiler is fired, the 260 aims to increase the boiler supply water temperature to at least the BOIL MIN setting.
All control functions and specifications are listed in the Product Catalog I 000 and Data Brochure D 260.