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Frequently Asked Questions

If you can’t find what you are looking for, please contact us, and one of our team will be happy to help.

1My MC200/MC300 displays 'SERVICE DUE'

When the MC200 is installed the Commissioning Engineer may have entered a date for when the heating equipment requires servicing.
When this date is reached the MC200 fault indicator will be illuminated and the display will alternate between the normal display and "Service due, call engineer".
The Service Engineer can clear this display by entering a new service date when the heating equipment has been serviced.

2No Mains supply to heat in/fan in terminals

If there is voltage at the mains terminals (L,N & E) and there is no mains supply on the Heat In or Fan IN terminals and you are utilising terminal 14 (L Out) to energise these terminals, then the 6.3A fuse requires replacing.
*Isolate the power and remove the controller facia pad. Pull off the clear plastic fuse cover and replace with new fuse.
(* only to be achieved by a competent person)

3My MC200/MC300 has no Heat On illuminated although I am calling for heat

Pressing the Heat Button has no effect - no heating on LED.
1. The room temperature may be greater than the set point.
Navigate to the 'Temperature' setting and increase the day set point using the + button.
If the temperature wont adjust, check the permissions setting.
If the temperature doesn't increase past a particular point, the range could be limited within the engineers setting.
Go to the Engineers settings and increase the maximum available temperature.
2. The heat button may be turned off within the permissions settings

4My MC200/MC300 has a blank screen

A blank screen is present on the display but the backlit light is still on.
Before replacing the MC200 ensure the controller has been powered up for more than 48hrs.
If the screen is still blank, isolate the power and remove the controller facia pad. Ensure the ribbon cable is connected to the pcb and pushed in tightly to its terminal housing on the backboard.
*With the power back on check the display. If still blank, push the power reset button on the rear of the pcb. (*only be undertaken by a competent person.)
If the screen remains blank, contact Powrmatic technical department.

5My MC200/MC300 displays 'HEATER LOCKOUT'

'Heater lockout' appears on he display if the MC200 receives a fault voltage onto terminal 7. The Fault LED will also be illuminated.
The lockout can be cleared by pressing the reset button on the front of the controller. This will send a pulse of neutral back up to the heater to remove the lockout condition.
If the lockout continues to display once the reset has been pressed, it may mean the interconnecting reset cable to the heater is not wired correctly or the heater has developed a permanent fault that requires a service engineer to identify.

6My MC200/MC300 displays 'SENSOR FAULT'

'Sensor fault' appears when there is a break in the circuit between terminals 'SEN1' and 'COM' or if fitted, 'IN2 and
This could be either a faulty sensor bead, an incorrect terminal connection or a break in a cable.

7My MC200/MC300 displays 'CLOCK FAILURE'

'CLOCK FAILURE' will appear on the screen if the in-built battery has gone flat. This specially occurs if the power has been turned off to the controller for a long period. Leave the power connected for at least 48hrs to re-charge the battery (one whole week is more realistic dependent on the age of the battery itself).
Also check the ribbon cable between the two pcb's is making good contact.

8How do I replace a Limit Interlock PCB on a NVx heater?

Copy the following link into your browser:

9What terminal number on a NVx is heat demand?

Heat demand comes in on Terminal 1

10Do I need a condense drain in my flue stack if running my flue vertically?

If the heater is a standard unit with an on/off burner, then there is no need for a condense drain because of the consistently high flue gas temperatures. If the heater is fitted with a high/low or modulating burner, then a condense drain must be fitted due to the lower flue gas temperatures when the heater runs on low fire

11Can I run NVx flue horizontally or vertically?

You can run flue in either configuration. The heater is factory-fitted with flue connections on the rear of the heater, but these are easily converted to the top of the heater if required by the installer.

12What is the maximum permissible flue length I can connect to an NVx heater?

If connecting flue only, then it’s 12m maximum. If connecting both flue and combustion air, then it’s half of this figure - 6m maximum. If using a 45° bend, this is equivalent to 0.5m of flue length. 90° bends may be used but will be equivalent to 1.0m of flue length.

13What are the flue sizes for the NVx range?

The NVx15-25kW is 80mm dia, NVx30-50 is 100mm dia and NVx60-140 is 130mm dia flue


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