What is the Dometic FJZ motorhome air conditioner?
The Dometic FJZ is a roof-mounted air conditioning unit designed specifically for motorhomes, campervans and caravans. It replaced the previous FJX series and brings improved energy efficiency, a lower profile roofline, and quieter cabin operation, making it one of the most popular motorhome air conditioning units in the UK market.
Thermo Technica is a UK specialist stocking the full Dometic FJZ range. Whether you’re replacing an older unit or fitting air conditioning for the first time, our team can advise on the right model and capacity for your vehicle.
Dometic FJZ models and cooling capacities
The FJZ range comes in several cooling outputs to suit different motorhome sizes:
| Model | Cooling Capacity | Best For |
|---|---|---|
| Dometic FJZ 2200 | 2,200W | Campervans and smaller motorhomes up to 6m |
| Dometic FJZ 3000 | 3,000W | Mid-size motorhomes 6–7.5m |
| Dometic FJZ 3500 | 3,500W | Larger A-class and coachbuilt motorhomes |
All models include a roof unit and a distribution box that directs cool air into the cabin. Optional ducted versions are available for fully integrated airflow.
How does the Dometic FJZ differ from the FJX?
The FJZ is the direct replacement for the Dometic FJX series. Key improvements include a redesigned compressor that operates more quietly, a slimmer roofline profile that reduces wind drag, and updated controls compatible with the Dometic ONE app. If you’re currently running an FJX and considering an upgrade, the FJZ uses the same roof cut-out dimensions on most installations — making retrofitting straightforward.
Read our full comparison: [Dometic FJZ vs FJX: What Has Actually Changed?]
Installation and compatibility
The Dometic FJZ requires a 230V mains hook-up connection or a sufficiently sized inverter for off-grid use. It mounts onto a standard 400x400mm roof cut-out (same as the FJX), though we recommend professional fitting to ensure weatherproofing and correct wiring. Our team can advise on compatible Victron inverters and lithium battery setups for sites without hook-up.
Why buy your Dometic FJZ from Thermo Technica?
- Nearly 30 years of motorhome climate specialist experience
- UK-based technical support Monday to Friday
- Full Dometic warranty backed by an authorised UK supplier
- Honest advice we’ll tell you if a different model fits your needs better
Frequently Asked Questions
Can I run a Dometic FJZ off solar and batteries?
Yes, with the right setup. A 3,000W FJZ draws approximately 8–10A at 230V. You’ll need a high-quality pure sine-wave inverter and sufficient lithium battery capacity — typically 200 Ah+ for meaningful off-grid runtime. Contact us, and we’ll spec the right system for your motorhome.
Does the FJZ work as a heater too?
Some FJZ models include a heat pump function for mild weather heating. For primary winter heating in the UK, we’d recommend pairing with a Truma or Dometic diesel heater.
Is fitting a Dometic FJZ a DIY job?
The mechanical installation is manageable for confident DIYers, but a qualified electrician must carry out the 230V electrical connection. Most customers prefer to have a professional fitter complete the full installation.
What is the warranty on the Dometic FJZ?
Dometic provides a 2-year manufacturer’s warranty on the FJZ range when purchased from an authorised supplier. Thermo Technica is an authorised Dometic stockist.