Frequently asked Questions:

“General” Questions:

What does the Nilan Compact P do?

The Nilan Compact P provides you with Ventilation, Hot water and some heating/cooling. It is also the “switch” that turns on and off some of the additional radiators in your home.

Is the Nilan Compact P meant to run continuously?

Yes, your Nilan Compact P must run continuously to provide your home with a constant supply of fresh air. Allowing it to run continuously also allows it to create all the hot water. Turning off your Nilan Compact P will cease both functions.

What is the most cost-efficient way to operate my Nilan?

Your Nilan Compact P contains heat recovery ventilation, a heat pump and a hot water cylinder. Once the heat pump has replenished the hot water cylinder, it will divert its energy to the supply air being delivered to the living rooms and bedrooms, raising its temperature. It is (approx.) 3 times more economical to use the heat pump to supply thermal energy than using direct electric.

The following suggestions will help to reduce your energy consumption for using the Nilan MVHR and electric radiators. These suggestions will also reduce your overall energy consumption of your residence:

  1. Reduce the desired hot water temperature of the cylinder low enough to meet the needs of your home. Reduce it by 5 degrees every day until you are satisfied it is the right level to meet the needs of your home. By doing this, excess hot water will not be produced and the Nilan will therefore spend more time heating the supply air going to the rooms and, in turn, reduce the demand on the convector/infra-red radiators.
  2. When your Nilan starts to make hot water, it is unable to heat the supply air going to the bedrooms and living room. If there is a demand for space heating, the Nilan will turn on the electrical radiators. To reduce the effect of this scenario, you could use an “Offset”. This setting is described in more detail below in the “The air coming out the vents is cold; how can I get more warm air?” FAQ.
  3. Reduce the property desired “setpoint” temperature by one or two ° if its comfortable to do so. A small reduction will still help reduce energy usage.
  4. Choose your electrical tariff. Direct electric has more than doubled in price in recent years (Oct 2021 – Oct 2022) so it is prudent to shop around to get the best deal.
  5. Implement a User Profile to make use of a night-time tariff. With some night-time tariffs as low as 4.5p per kWh, you could set your Nilan to a higher-than-normal temperature that will force on the direct electric radiators during off peak hours. This will reduce the use of the radiators during peak tariff hours.
Will opening the windows damage or affect the ventilation system?

No. As per any house, on the colder days of the year you may find some localised drop in temperature with an open window, but on the warmer days opening windows will help to regulate internal temperatures.

Can I turn the Nilan Compact P off?

You should only turn your Nilan Compact P off only when it is time to clean/change your filters. There is no need to turn off the system other than for this purpose.

How do I turn the Nilan Compact P off?

You can turn off the Nilan Compact P by entering the settings menu, selecting run mode and selecting off. When you hear the fans slow down and stop you will be able to clean/change the filters.

When should I replace the filters?

How often you need to change your filters is dependent on where you live. High polluting areas result in the filters needing to be changed more frequently. Check your filters every 3 months to see if they are keeping dirt out. Clean filters will offer less resistance to the fans than dirty ones. Over time, cleaner filters will mean the fans lifespan are increased. 

Can my Nilan Compact P be replaced?

Every part of your Nilan can be replaced individually. To order spare parts, email: aftercare@nilan.uk.com

What do the 4 ventilation speeds mean?

You can change the ventilation speeds by tapping the fan icon and pressing the up and down arrows. Use the following scenarios to help dictate the fan speeds:

  1. On holiday / night-time / low relative humidity
  2. Regular occupancy / everyday use
  3. High occupancy / family gathering / bypass and / or active cooling.
  4. Very high occupancy / high relative humidity
What is air humidity?

Air humidity is a measure of how much water the air is holding compared to its capacity, expressed as a percentage. The number with a % symbol next to it is the relative humidity of the indoor air, as measured by the Nilan extracted from the bathrooms and kitchen.

The Nilan will boost ventilation when the relative humidity increases by a set amount above the rolling average. This means that the machine will not use energy trying to maintain a set humidity and will only work to remove excess humidity.

Why is my Nilan Compact P at fan speed level 1 when I have it set at level 2 or above?

During winter when it is cold and crisp outside, the relative humidity in your home is likely to be lower than in summer. When the relative humidity in your home falls below 30%, the machine will reduce the ventilation to level 1 so that the humidity in the property can return to a level above 30%. This feature is part of the smart Nilan technology which creates a comfortable, healthy indoor climate.

Why is my Nilan Compact P at fan speed level 4 when I have it set at level 3 or below?

The relative humidity in your home can increase after a shower, washing up, laundry etc, or during summer. When the relative humidity in the property has increased above the rolling average, the machine will increase the ventilation level so that the humidity in the property can return to normal level. This feature is part of the smart Nilan technology which creates a comfortable, healthy indoor climate.

The air coming out the vents is cold; how can I get more warm air?


This is likely due to the room temperature being achieved and no additional heat being required. The Compact P will continue to provide fresh air until additional heat is required to meet the set room temperature.

What do I do if there is a warning or alarm triangle displayed on my machine?

If a triangle with an exclamation mark inside is displayed, it is most likely to be the reminder to change the filters. On the unlikely occasion it isn’t, it will mean there is a warning or alarm that needs to be investigated. Tap on the triangle with the exclamation mark and it will take you to a brief description of the warning or alarm.

  1. If it is a warning, either follow the on-screen instructions or email aftercare@nilan.uk.com. Once the actions for the warning have been followed the warning can be reset by pressing “Clear Alarm” on the touch screen.
  2. If it is an Alarm, the unit will have stopped operation as this indicates a fault and will need investigation by an expert. Email aftercare@nilan.uk.com so we can investigate and take the appropriate action.

“Hot water” related questions:

How do I increase my hot water temperature?

Tap on the hot water cylinder icon on the bottom left corner of the screen and raise the temperature sufficiently to meet your family’s needs. By keeping the hot water temperature as low as possible, the unit will spend more time actively heating the supply air thus reducing your homes dependence on the auxiliary radiators.

My hot water appears to be hotter than my set point but still appears to be making hot water. What should I do?

Your hot water cylinder contains two temperature probes. One at the top of the tank and one at the bottom. You will see the top of tank temp on your screen; however, it is not until the temperature probe at the bottom of the tank reaches the hot water set point will hot water stop being produced.

The weather has gotten colder, and it is taking longer to make our hot water. Is there anything I can do?

In periods of excessively cold weather, there is less energy in the incoming outside air for the system to draw from. This means it may take slightly longer to generate the same volume of hot water. If you find you are running out of hot water, try increasing the hot water temperature.

If you need hot water more quickly, try using the electrical supplement heater hot water. To do this, see “How do I use the supplementary hot water heater”.

Note: the electrical supplementary heating will initiate when the hot water temperature (measured by the thermocouple at the top of the hot water tank) drops below the point specified. Undo this setting after the cold period as it does consume more electricity.

How do I use the supplementary hot water heater?

The supplementary hot water heater is concentrated at the top of the tank. This means it will warm the top third of the tank and will not use extensive amounts of energy. The supplementary hot water heater switches off once the temperature at the top of the tank meets the temperature the electric supplementary heater hot water has been set to. To use it:

  1. In the main menu choose domestic hot water
  2. Select electric supplement heater hot water
  3. Raise the temperature to a point to meet your needs.

Be sure to turn off the electric supplement heater hot water when not needed as it can lead to higher energy usage.

I have no hot water, what could be the reason?

Has your hot water set point been set at a sufficient level to meet the needs of you home? If you had hot water but it has run out, try raising the hot water temperature to a point that meets your needs.

Does turning up the fan speed make more hot water?

The hot water tank is 180ltrs. Turning up the fan speed won’t make any additional hot water, but it will warm it faster. More ventilation means more air over the heat pump which means more energy can be put into producing hot water.

How do I change the day for anti-legionella operation?

In Service settings, select domestic hot water, and then select day for legionella. Choose the desired day. Monday will have been set during commissioning; therefore it is not necessary to change.

“Cooling” related questions:

What is Active Cooling?

The Nilan Compact P is not an air conditioning device. Like active heating, which introduces a small amount of energy to the air going to the bedrooms and living rooms, active cooling only removes a small amount of energy, thus gently cooling the supply air.

Why is the Nilan not cooling my home?

Do you have the active cooling activated? If not, then see point below for “How do I use the active cooling”.

If yes, see following advice. The active cooling can provide a small amount of cooling and therefore works with other strategies for maintaining a cooler environment during warmer months. Other strategies involve stopping solar gain using external shading, blinds or curtains, maximising night-time ventilation through opening windows upstairs and “half latching” downstairs to maintain security.

How do I use the active cooling?

The active cooling setting will help maintain a comfortable indoor environment in the summer months. At commissioning, the default value for initiating active cooling will have been set to “Setpoint+5”. If you want to change this, go into settings, then select the cooling option. In this menu, select cooling setpoint and increase or decrease the value. The higher the value, the longer the Nilan will wait before starting the active cooling.

What level should I set my Nilan at for cooling?

During commissioning, the ventilation level for cooling will have been set at level 3. If this level is too high or too low, it can be changed in the cooling menu. Select ventilation in cooling mode and change the ventilation to the desired level.


Miscellaneous questions:

Do I need to set a week programme?

No, your home is designed to be maintained at a constant temperature. That said, there is the function available to use if you would like to set a week programme. Please be mindful that the heating system is designed to use as little energy as possible, therefore if the property is allowed to cool it may take several hours to warm back up. A week programme is a handy way in which to make the most of cheaper night-time electricity tariffs.

What setting should I use when going on holiday?

When on holiday, leave the Nilan Compact P running as it is keeping the house ventilated so that excess humidity and other home pollutants do not build up. It also controls the heating and will ensure the temperature doesn’t drop too low if holidaying at winter. To save energy, reduce the fan speed to level 1 and either allow the home to cool slightly if it’s over winter or warm slightly if its summer.

Note: once the Nilan App is connected these settings can be changed remotely.

I'm getting strong smells into my house, should I turn the Nilan off?

Strong smells in the house are likely to be cooking smells from neighbours. This is normal for all ventilation systems! It is not advised to turn off the Nilan unit as this will result in poor air quality and loss of heating and hot water.

Can I change the air vents in the ceiling and floor myself to get more air flow?

No, the vents are positioned so that the amount of air flowing into the property is balanced with the air exiting the property. Changing the vents may increase or decrease the overall supply or extract flow. This may lead to the system not being balanced and not being as efficient as it could be. This could lead to higher energy bills.

My question is not listed.

If you have a question that hasn’t been answered above, contact one of the following:


Jump to: General /Hot Water / Cooling