Questions and answers

Do you have an administrative question or a technical question? First of all, see if it is listed below.

If this is not the case, please call our customer service department at 085 – 004 43 76 or send your question to us via

We will respond to your question as soon as possible.

Administrative questions

Can I get a contract for electricity at Warm Kop Grasweg as well?
No, unfortunately this is not possible. Warm Kop Grasweg only provides sustainable heat supply and not electricity supply.
What are the tariffs?
The rates can be found on the rates page..
What do the items on my year-end statement mean?
The rates are set annually by the Consumer & Market Authority. Hereby an explanation of the rates for 2020:
  • Warmth: the rental of the delivery set. The delivery set is the installation needed to bring the hot water from the hot cold storage system safely to the indoor installation for space heating and/or domestic hot water preparation.
  • Domestic hot water comfort 10 l/min: the availability of 10 liters of hot water per minute. This means that there will be enough hot water for a rain shower or the possibility of having hot water available simultaneously in the kitchen and the bathroom.
  • Heat exchanger: heats the cold drinking water that flows to the hot water taps in the kitchen or bathroom. This is done via a separate system. As a result, the drinking water does not come into contact with the hot water from the WKO system.
  • Measuring rate: costs for measuring your heat consumption. This is achieved by measuring the inflow and outflow of heat in your home with a calibrated meter. The difference is the heat output measured in m³ (hot water) or GJ (heat).
  • Cold: fixed fee for the provision of cooling.
What are the features of the customer portal?
In the customer portal, you can update your personal data, view your consumption, view invoices and change your deposit amount.
I want to change my deposit amount or something else. How do I do this?
Via het klantenportaal kunt u eenvoudig uw voorschot aanpassen. Dit doet u via Instellingen, Voorschot, Wijzigen. Vanaf het eerst volgende facturatie moment gaat het gekozen voorschotbedrag in werking. U kunt hiervoor uiteraard ook contact opnemen met onze medewerkers van de klantenservice via telefoonnummer 085 - 004 43 76.
I want to change my payment method. How do I do that?
Via het klantenportaal kunt u eenvoudig uw betaalwijze aanpassen. Dit doet u via Instellingen, Gegevens, Wijzigen. U heeft de mogelijkheid te betalen met automatische incasso of iDEAL. Als u kiest voor iDEAL ontvangt u maandelijks een e-mail met de factuur. U kunt het bedrag ook maandelijks naar ons overmaken.
I'm a new resident. How can I register?
You can submit your application to us online by filling out the form on the registration page.
I'm moving soon. What should I arrange?
You can notify us of your move online by completing the form on the move out page.
A family member/acquaintance has passed away. What do I need to arrange?
Our customer service representatives will be happy to help you by calling 085 - 130 48 29.
  • Will the property stay within the family (for now)? Then the new owner can register one the page sign up.
  • If the lease is terminated or the house is sold, you can fill out the form on the page move out. Under Who fills out this form? choose I am filling out the form for a deceased family member/acquaintance.
Can I pass on my own meter readings?
You do not have to pass on your meter readings to us. We can digitally read your energy meter from a distance. You can also find the readings and your consumption on a monthly basis in the customer portal. Only the starting meter reading on moving in (for the Supply Agreement) and the ending meter reading on moving out (for the Moving Out Form) need to be signed and submitted on the date. This will be asked for in the documents you send us.
Can I pay by direct debit?
Warm Kop Grasweg heeft het liefst dat u via een automatische incasso betaalt. Tijdens de eerste keer inloggen heeft u hier wel of niet voor gekozen. U kunt uw betaalvoorkeuren wijzigen in het klantenportaal.
What is the privacy policy of Warm Kop Grasweg?
Our privacy policy can be found on this page.
What are the terms and conditions for connection, delivery and general terms and conditions?
See the PDF documents on our page documents.
In the customer portal it says that I have not paid an invoice. This is not correct. What about this?
In principle, we update the incoming payments every Monday. We therefore ask for your patience before the payment is visible. If you receive a reminder e-mail even though you have already paid the invoice, please contact our customer service staff via telephone number 085 - 004 43 76 or
How can I (financially) sustainably use my heat installation?
  • Every 2-3 hours the system checks if it needs to heat/cool. It takes 8-10 hours before the room temperature can be adjusted to the requested temperature. If you want to go from a low temperature to a high temperature, this costs extra power. That is why we recommend that you leave the thermostat at a constant temperature;
  • Try not to leave windows and doors open unnecessarily to avoid heat/cold loss;
  • The balance ventilation on a normal/low setting reduces the flow of cold/hot outside air into your home;
  • It is important that the floor heating can properly dissipate the heat;
  • Handle tap water sparingly.

Technical questions

What should I do in case of a calamity or malfunction?
Please take a look at our page Malfunctions. In the event of an emergency (major malfunction), you can always contact us directly by phone at 085 - 004 43 76 (choose 1). If you are unsure about the severity of the fault, you can also choose Other questions and consult with our customer service.
Are there now (or soon) any works on the system?
In case of scheduled servicing or updates about malfunctions, we will post a news item on the page Malfunctions.
How can I read my heat meter / hot water meter?
The energy meter manual, like all other important documents, can be found on the documents.
How do I turn on the cooling?
Cooling starts when you turn on the automatic heating/cooling control. You set the program AUTO by pressing and holding the P button until AUTO appears on the display. Cooling starts when the room temperature has reached the lower limit of 23 °C and is at least 3 °C higher than the desired temperature. When the cooling starts you will see a snowflake on the display. After some time the underfloor heating distributor should be 16-18 °C.


Further questions

Is your question not listed here? You can reach us via our contact details at the contact page.