Best Replacement Units for an Old Central Vacuum

How we chose

A replacement has to do one thing a new install does not: fit what is already in the wall. That means 2-inch pipe, a two-wire low-voltage inlet circuit, a bracket location with an outlet nearby, and, if you want to keep buying the same bags, a matching bag. We ranked these five on how little they ask you to change, then on manufacturer-published air watts and water lift, filtration, warranty conditions and inlet support. All five use 2-inch pipe. Four list both low-voltage and direct-connect electric inlets; the Drainvac lists low-voltage only.

One pick is discontinued. We include it because so many readers search for it by name, and we explain what that means for warranty.

1. Drainvac MP-Air 550: best NuTone replacement

If you are replacing a NuTone, the MP-Air 550 asks the least of you. It uses the 391C disposable bag, has a 22.7 L (6 gal) canister, a utility inlet on the unit, a 6 ft cord and a wall-mount support, and publishes 550 air watts and 66 dB with a 4,000 sq ft rating. The Amazon listing, sold by Drainvac’s parent Metal MP, says it integrates with NuTone systems and has a multi-direction inlet. Its capacity, bag, noise and 13.25 x 29.75 in footprint match the discontinued PP5501 closely, though no source says they share a platform. Warranty is 5 years on the power unit and 3 years parts and labor, possibly limited if not registered.

Water lift and CFM are not published, and Drainvac lists low-voltage inlet control only.

Skip it if your old unit was a 650 or 700 air watt PurePower and you do not want to step down in suction.

2. NuTone PurePower PP6501: best if you find one (discontinued)

The PP6501 is the mid PurePower unit: 650 air watts, 125 in water lift, 13.5 A, 64 dB, 25.5 lb, rated for 7,000 sq ft. It ships bagless (cyclonic mode) with a sealed HEPA permanent filter, and a bag adapter lets you run a 391 bag instead. The bracket, 6 ft cord, debris pail and low-voltage crimp connectors are in the box; NuTone recommended a 20 A circuit. Warranty was 8 years on parts with the first 5 years labor, though the product page’s table says 5 and 3.

Broan-NuTone marks it discontinued, and its site says the NuTone central vacuum line is now owned by Drainvac. The Drainvac page for the NuTone line returned a 404 in October 2026, so who honors the warranty on a new-old-stock unit is unclear. It ranks second because the fit is exact for PurePower owners and bags remain available.

Skip it if you want a warranty you can rely on.

3. OVO 700ST-35H: best upgrade

If the old unit died and you want better, the OVO 700 is the swap most homes should make. It publishes 700 air watts, 140 in water lift and 63 dB from a 5.7 in 2-stage thru-flow motor, rated for 8,000 sq ft and 8 inlets, and the 35 L hybrid canister runs with a 22.5 L bag or bagless. The MUSUP wall bracket, one bag, the FP-12 permanent filter, a 6 ft grounded cord and a low-voltage wire socket are included. Warranty is 10 years on parts, 1 year labor, with an optional paid 25-year extension; the filter must be replaced every 2 years.

OVO’s warranty asks for proof of purchase “along with the invoice for the installation by a qualified electrician”, so keep both. The unit was not on OVO’s own storefront in October 2026.

Skip it if you want to keep your 391 bags.

4. VacuMaid SR66: best bagged replacement

The SR66 fits any 2-inch system with low-voltage or direct-connect inlets, and its Ametek Lamb 6.6 in 2-stage tangential bypass motor is rated for about 1,500 hours. It publishes 663 air watts, 139 CFM, 132 in water lift and 58 dB vented with a 10,000 sq ft rating, uses HPB2H HEPA-style bags (27 qt), and is listed as Hide-A-Hose compatible. Lifetime canister warranty, 10 years on the motor; claims go first to the authorized dealer-installer.

VacuMaid’s page and spec sheet disagree on height (36 in versus 26 in), so measure your wall against the taller figure.

Skip it if you want a hybrid.

5. Beam 475: best for Beam owners

An old Beam is best replaced by a new one through a Beam dealer, who will also check the bracket and intake position. The 475 publishes 659 air watts, 144.9 in water lift and 135.8 CFM with a 10,000 sq ft rating, and its Hybrid Gore filter runs bagged or bagless. Warranty is 10 years or 750 hours on parts and 1 year labor (a second table shows 7 years for this model). Beam has been owned by Trovac Industries since June 2024; only units manufactured from September 2024 carry the Trovac warranty. The Amazon listing is a third-party dealer.

Skip it if you want to buy online.

What to check before you buy

• Pipe position. Note where the 2-inch stub enters the old unit (top, side, height from floor). You may need a flex section or coupling. See pipe and fittings.
• Low-voltage wires. Two wires, usually a thin pair. Every unit here has terminals for them. Low-voltage wiring guide.
• Inlet type. Confirm with identify your inlet type. Direct-connect electric inlets keep their own 120 V circuit; do not touch it without a licensed electrician.
• Bracket and outlet. New bracket, new holes, and a 120 V outlet within cord reach (6 ft for the Drainvac, OVO and NuTone).
• Exhaust. Reuse the existing exhaust run if it is 2-inch pipe to outside.
• Bags. 391-series for Drainvac and NuTone; HPB2H for VacuMaid; FD-22.5L for OVO.

What to do next

Read replacing an old unit for the step-by-step swap, and troubleshooting lost suction first if you are not certain the old unit is dead; a motor replacement costs a fraction of a new unit. If you decide on a swap, order bags and, if you want an electric powerhead, the right hose at the same time.