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DEL Ozone Ozonators: Model Guide, Replacements and Parts
Affiliate disclosure: As an Amazon Associate, Delozone earns from qualifying purchases. Some links on this page are affiliate links, so we may earn a commission at no extra cost to you.
Independent guide: Delozone.com is an independent publisher. We are not DEL Ozone, CMP or any of their dealers, and we cannot handle warranty claims, orders or repairs. DEL Ozone is now a CMP (Custom Molded Products) brand, so for warranty questions contact CMP or the dealer who installed your unit.
A lot of hot tubs and pools built in the U.S. and Canada over the last 25 years left the factory with a DEL ozonator inside. If you are here, you probably own one, it has stopped doing its job, and you want to know which model you have and what to buy next. This page pulls together what we know about the DEL range, old and current, and the realistic replacement paths for each.
Quick answer: my DEL spa ozonator stopped working
- Confirm it is actually dead. A dead cell and a clogged check valve look the same from the outside. Our spa ozonator test guide takes about 10 minutes.
- If only the cell has worn out, try a module kit. DEL’s own MCD-50 renewal kit has been discontinued by several retailers, but compatible 9-1056-01 module kits are listed for the MCD-50, EC-10/20/40 and DEL Ozone 25/50/100. Check the 9-1056-01 module kit on Amazon. It has only a handful of reviews so far, so read them before you order.
- If the unit is older than about 5 years, replace the whole ozonator. A plug-in corona discharge unit in the HCD-55 style is the simplest swap for most 110V spas. Check the HCD-55 spa ozone generator on Amazon. For a like-for-like DEL part, ask a CMP dealer about the current DEL Ozone Spa unit.
Replacing an MCD-50 specifically? Our DEL Ozone MCD-50 replacement guide covers renewal modules, compatible ozonators and how to do the swap.
Which DEL ozonator do I have?
The model name is printed on the label on the side or top of the housing. If the label has faded, the shape, the voltage and the year of the spa usually narrow it down.
| Model | Application | Technology | What to know |
|---|---|---|---|
| CDS-16 | Portable spas (OEM) | Chip-based corona discharge | Factory installed by spa makers from 1998. Any surviving unit is well past its expected cell life. |
| Spa Eclipse | Portable spas | Corona discharge, dual voltage | Sibling of the CDS-16. Replace rather than repair. |
| MCD-50 | Spas up to about 1,000 gallons | Corona discharge (APG cells, roughly 50 to 70 mg/hr) | The most common DEL spa unit. The DEL renewal kit is listed as discontinued by retailers; compatible module kits exist. |
| Spa Solar Eclipse Plus | Hot tubs and swim spas up to 3,000 gallons | Ozone plus UV-C (AOP) | Larger swim spas. Needs both the ozone cell and the UV lamp serviced. |
| DEL Ozone Spa (current, CMP) | Spas up to 1,000 gallons | Corona discharge, adjustable output around 50 mg/hr | Very compact (about 2.6 x 3.3 in). The current like-for-like replacement sold through CMP dealers. |
DEL pool ozone generators
On the pool side, DEL sold the Eclipse-1, Eclipse-2 and Eclipse-4, rated for pools up to 25,000, 50,000 and 100,000 gallons. The later EC-10, EC-20 and EC-40 codes belong to the same family. Above-ground pools had the Big Dipper, and the Total Eclipse added its own circulation pump so it could run independently of the main pump.
Under CMP the current line is the DEL Ozone 25, 50 and 100 (named for the pool size in thousands of gallons) and the DEL AOP 25, 40 and 50, which pair ozone with UV. If you are replacing an Eclipse, start with the model that matches your pool volume, then check the plumbing: the injector and check valve on a 10 year old install are often due too.
If you are open to other brands, our pool ozone generator comparison covers the current options by pool size, and how to size an ozone system explains the numbers.
Commercial DEL systems (CD-2 to CD-500)
DEL’s commercial range ran from the air-cooled CD-2 (about 2 g/hr, 115V) up to the CD-500. Units from the CD-15 upward were water-cooled, and the larger ones used oxygen concentrators. These were sold as engineered systems with safety interlocks and destruct units, so replacements should go through a commercial dealer or CMP rather than a retail listing. For background, see our commercial ozone water treatment guide.
Parts that fail before the ozonator does
In our experience answering reader questions, the cell is often blamed for problems caused by the parts around it:
- Check valve. When it fails, water backs up into the ozone line and can kill the cell. Replace it whenever you replace the ozonator.
- Ozone tubing. Ordinary vinyl turns brittle and cracks. Use ozone-resistant tubing; our material compatibility chart lists what holds up.
- Injector (venturi). A clogged injector means no suction and no ozone in the water, even with a working cell.
If the unit hums but you smell no ozone at the tubing outlet, work through the hot tub ozonator troubleshooting guide before buying anything.
Choosing a replacement
If you want to compare the replacement ozonators we would consider today, including DEL, Prozone and Balboa-compatible units, see the best hot tub ozone generators. For the maintenance schedule once it is installed, see how often to replace an ozone generator.
FAQ
Is DEL Ozone still in business?
The DEL Ozone brand is still sold, but it is now part of CMP (Custom Molded Products). Current spa and pool units, as well as warranty support, go through CMP and its dealers.
How long does a DEL spa ozonator last?
Corona discharge cells in spa ozonators typically lose output after about 3 to 5 years of normal use. If your spa is older than that and the water needs more sanitizer than it used to, the ozonator is a likely cause.
Can I run my spa without the ozonator?
Yes. Ozone is a supplement, not the primary sanitizer. Without it you will simply need more chlorine or bromine to keep the water clear, so keep a closer eye on your test strips until it is replaced.
Is delozone.com the official DEL Ozone website?
No. Delozone.com is an independent guide to ozone water treatment. For official product information, contact CMP.
