nJoin Power Module with Class A GFCI
Notices
Quebec Repairability Notice
Avis important pour les consommateurs du Québec:
WarmlyYours ne fournit ni services de réparation ni pièces de rechange pour ce produit. Si votre thermostat de chauffage de sol intérieur tombe en panne pendant la période de garantie, nous remplacerons l'unité complète conformément à notre politique de garantie. Notre équipe de soutien technique est disponible par téléphone 24h/24 et 7j/7 pour l'assistance à l'installation et au dépannage. Pour tous les détails, veuillez consulter notre Politique de Retour. Cet avis est fourni conformément à l'article 39 de la Loi sur la protection du consommateur du Québec (telle que modifiée en 2025).
Important Notice for Québec Consumers:
WarmlyYours does not provide repair services or replacement parts for this product. If your indoor floor heating thermostat fails within the warranty period, we will replace the entire unit according to our warranty policy. Our technical support team is available 24/7 by phone for installation and troubleshooting assistance. For full details, see our Return Policy. This notice is provided in accordance with Québec’s Consumer Protection Act, section 39 (as amended in 2025).
nJoin Power Module Description
Some floor heating jobs are just too large for a single radiant heating thermostat to handle alone. The nJoin power module is here to help you heat those larger projects. The refined and modern-looking nJoin links up to any WarmlyYours thermostat in the nSpiration series (nSpire Touch WiFi, nSpire Touch, nHance, or nTrust) to increase the electrical output in 15 amp increments to allow for heating additional areas or large rooms, like basements, with a single thermostat.
Screw terminals for safe and easy installs
- 3-year warranty
- Built-in self-testing GFCI
- Dual voltage: 120 V and 240 V
- cULus Class A approved
Specifications
Warranty / Certifications
| Approvals | cULus listed |
| Ingress Protection (IPxx) Rating | IP21 |
| Warranty | Limited 3-year warranty and lifetime technical support |
Electrical
| Connection | 4 wires, double pole |
| Connection Method | Hardwired |
| Ground Fault Protection | GFCI, Class A, 5 mA |
| Maximum Current | 15 A |
| Maximum Power | 1800 W @ 120 V, 3120 W @ 208 V, 3600 W @ 240 V |
| Supply | 120 VAC, 208 VAC, 240 VAC (50/60Hz) |
Product Dimensions
| Depth | 2″ |
| Installed Depth | 0.8125″ |
| Length | 4.688″ |
| Weight | 0.55 lbs |
| Width | 2.875″ |
Identifiers
| SKU | USG-4000 |
| UPC (GTIN-12) | 881308051259 |
Documents
Installation
Operation Manuals
Wiring Diagrams
Frequently Asked Questions
While WarmlyYours electric radiant floor heating systems are typically installed by your floor covering contractor, a licensed electrician is recommended for the final thermostat hook-up. With every quote, we provide an Installation Plan layout, together with an electrical plan that has all the info required for the electrician.
You can use the Instant Quote Tool, which gives you many options for your floor heating coverage. Use this interactive tool to design your room online and receive an instant quotation with product recommendations, rough-in and installation kits, cost of your control, etc. Planning your floor heating project is made easy when using our Instant Quote Tool.
Send us your floor plan or fax it to (800) 408-1100 and we will send you a quote, product recommendation and a free custom installation plan for your project.
Please keep in mind that you must check your electric floor heating system with a digital ohmmeter in conjunction with a Circuit Check™. Take an initial reading as soon as you take the product out of the box to verify that it is within -5% / +10% of the values stated on the product’s label. This will give you a basis of comparison for future readings. Take a second reading once you have positioned the system to match your custom installation plan. It is also advisable to take an additional reading in the middle of the tile installation, just to make sure that the Circuit Check™ is doing its job. Then, take a final reading when you are finished with the floor installation and are ready to hook up the thermostat.
The Circuit Check™ is a tool developed by WarmlyYours to give you peace of mind and ensure trouble-free installations. Simply hook up the cold leads to the tool while you position the system to match your custom installation plan.
The Circuit Check™ will continuously monitor the continuity of the circuit during the installation of your system and during the installation of your flooring. The Circuit Check™ beeps immediately when a short in the system is detected, alerting you to a potentially damaged cable in the area you are working, before you lay the tile over the electric floor heating system. The WarmlyYours technical support team is available 24/7 to provide assistance if the alarm sounds, or if you would have any questions during your installation.
Yes, in most cases, an electric floor heating system can be effective as a primary heat source. However, our TempZone™ and Environ™ systems are most commonly used as a secondary heat source, providing floor-to-ceiling radiant heat to any room in your home where you desire more warmth and comfort.
If you are considering electric floor heating for an addition to your home, such as a sunroom where you have no other source of heat, WarmlyYours offers an innovative online tool which calculates approximate heat loss. This tool can help you to determine if a WarmlyYours’ electric radiant floor heating system will provide your desired comfort temperature throughout the year. You can access the Heat Loss Calculator or you can call us at (800) 875-5285 and a Customer Service Representative will make the calculation for you.