Plumbing Connection; Free Standing - KERR Highlander Owner's Manual

HIGHLANDER WOOD–FIRED BOILER – INSTRUCTION MANUAL
2.6 PLUMBING CONNECTIONS
There are only two differences between the installation of any conventional hot water heating
system and those using a Kerr Highlander boiler – the safety override zone valve, and the
blow-down extinguishing system. A circulator of at least 5-G.P.M. capacity must be used in a
system using the Kerr Highlander boiler to assure circulation of water. Also the recommended
expansion tank size for the Highlander is a 12" Dia. X 36".
The normally open zone valve must be installed to allow a free flow of water in a power off
situation. Kerr recommends that the valve be placed as shown in Fig. TW-1 or Fig. TW- 4. The
override zone valve should be on the loop supplying the living area on the main floor level (i.e.
kitchen – living room). The override loop for the safety shall have at least 30 ft. of radiation
above the wood boiler. Do not use basement loop for the safety override loop, as this will not
provide gravity flow in a power out situation. This override loop must be capable of dissipating
at least 10% of the estimated heat output of the Kerr Highlander boiler in the event that the
circulation is reduced because of electrical power failure. The safety by-pass dump zone shall
NOT run through any plastic piping. A deliberate manual action shall be required to make the
override loop inoperative. The system is to be plumbed so that only a deliberate manual action
can make the override loop inoperative.
When the wood boiler is not satisfying a call for heat the water temperature in the boiler will
rise since the wood fire is still burning. When plumbing a wood boiler, ensure that the entire
heating system can handle the higher temperatures that can be sometimes generated. If there
is the possibility that the higher water temperatures can damage other parts of the heating
system including, but not limited to, in-floor radiant piping, then measures should be taken to
ensure that the water temperatures to these parts of the system are controlled. Controls such
as thermostatic valves can control water supply temperature (i.e. ESBE Thermic By-pass
Valve TV). Consult the manufacturer's instructions for the maximum permissible water
temperatures for in-floor radiant piping and/or other heating system parts.
The blow-down extinguishing system is installed to control the fire in case overheating causes
excessive pressure in the pressure vessel. The relief valve, included, is threaded into the top
of the pressure vessel and copper pipe is installed from its exhaust to the flange above the
loading door on the firebox.
In addition to its ability to heat the home, this boiler is provided with a domestic coil position. A
copper coil may be purchased with your boiler or added at a later date. It may be utilized as a
single water heater or in conjunction with an oil, gas or electric heater.

2.6.1 FREE STANDING

Free Standing installation requires additional components, which are not included in the
Highlander boiler kit. Check Fig. TW – 5 for additional required components.
In the freestanding or stand-alone system, the Kerr Highlander boiler is the sole source of
central heating. In this system connect the piping as you would for any conventional hydronic
heating system (using zone valves, circulator zoning, or single zone flow check system). The
boiler must not be installed as a gravity system, as the controls are not designed for this type
of operation. When installing the Kerr Highlander boiler as a stand-alone system, the boiler
may be wired in two ways. For the Stand-Alone wiring diagram, Fig. TW-5, a triple function
aquastat and an additional transformer must be purchased separately and installed in
place of the dual aquastat supplied with the boiler. The only special piping needed is the
HIGHLANDER 12 Nov-09