MHS Boilers Ultramax WM 100, Operating & Maintenance Manual, Page: 35 / 50

MHS Boilers Ltd ©
191007
35
6 Operating instructions
6.1 Operation
The fan, which is modulated by the temperature controller, supplies the combustion air. Due to
the resultant under pressure in the venturi, the zero pressure controller in the gas valve mixes in
the required quantity of gas. Gas and air are completely mixed in the venturi.
The gas-air mixture is then passed directly in to the burner. The fan also assists with the removal of
the combustion gases from the flue. The boiler has no lower limit to the return water temperature. If
this temperature is low, condensate will be formed, which is removed via the discharge system.
6.2 Controls
Depending on the heat requirement of the boiler, the load should be modulated between 14% and
100%. Below 14% load, the boiler operates on/off, based on temperature.
6.3 Boiler module KM628
Lid
closed Lid open
Fig.6 Boiler module
1 Function 1 Parameter indication
standby P1 current/setting boiler supply temp.
automatic operation P2 current/setting domestic hot water
summer operation temperature
service operation *P3 desired temperature
2 Function selector (Rotational Selector) P5 current external temperature
3 fault indication P8 current low velocity header temp.
4 supply temperature P9 current/maximum boiler capacity
5 malfunction code (flashing) P10 password entry for factory settings
6 operation mode 2 optical computer communication port.
night time reduction (no heating demand) 3 reset/programming push-button
heating mode (heating demand) 4 alarm LED
(flashing) burner operating 5 parameter/value selector
(Rotational Selector)
6 output status
7 current/desired parameter value
8 fault/parameter indication
9 input status
* P3 set load (in combination with KKM8/E8)