Direct Answer
Your WFCO replacement strategy depends on three things: which series your existing unit is (WF-8500, WF-8700, WF-8900, or WF-9500), what output amperage you need, and whether your footprint allows a same-series swap or a universal kit. WFCO offers in-brand replacement boards (MBA assemblies), full universal kits (REP series), and complete new power center units across the range.
This page covers the full WFCO model range at the overview level. If your goal is specifically the WF-8955 plus lithium compatibility, including the suffix matrix for every 8955 variant, see the dedicated detail page: WFCO 8955 lithium compatibility matrix and replacement options. That page owns that topic. This page covers the broader picture.
Step 1: Identify Your WFCO Series
Before buying anything, write down your exact model number. Where you find it depends on which generation you have.
Per WFCO's FAQ, verified on wfcotech.com on 2026-09-23:
- WF-8800, WF-9800, WF-6800, WF-5100 series: Model number is on the top label.
- WF-8500, WF-8700, WF-8900, WF-9900 series: Model number is on the inside front panel, next to the breakers.
Once you have the full model string (for example, "WF-8935" or "WF-8955-AD"), look at the digits after "WF-" and before any suffix. The first two digits identify the series family:
- 85xx: WF-8500 series. Two-circuit AC format, 9 branch circuits, 13 DC circuits. Available in 40 and 60 amp output.
- 87xx: WF-8700 series. Compact format, 3 to 5 branch AC circuits, 4 to 6 DC circuits. Output ranges from 12 to 40 amps. Suited to smaller trailers.
- 89xx: WF-8900 series. WFCO's broadest current lineup, 30A service with 5 branch AC circuits and up to 11 DC circuits. Available in 35, 45, 55, 65, and 75 amps. Includes the WF-8935-AD, WF-8945-AD, WF-8955-AD, WF-8965-AD, and WF-8975-AD.
- 95xx / 9580: WF-9500 series. Higher-capacity units, 40 to 80 amps. Physical footprint differs from the 8900 series.
If your model starts with WF-8935, WF-8945, WF-8955, WF-8965, or WF-8975, you are in the WF-8900-AD Series, which is WFCO's primary current RV power center line.
Step 2: Match Output Amperage
The two-digit number in the middle of a WFCO model number tells you the output amperage in the tens place:
- WF-835 = 35 amps DC output
- WF-845 = 45 amps DC output
- WF-855 = 55 amps DC output
- WF-865 = 65 amps DC output
A direct same-amperage replacement avoids having to resize your house wiring. Do not upsize to a higher-output unit without verifying that your existing battery cables and DC distribution wiring are rated for the added current. WFCO's FAQ states that the DC fuse sizes for each circuit are determined by the manufacturer: the fuse on each branch protects the wire, not just the device. Changing the converter output without confirming wiring adequacy is a safety concern.
Editorial recommendation: Match amperage to your existing unit unless you have a specific reason to upsize and have verified the wiring can support it.
To calculate what output you actually need for your load profile, use the converter sizing calculator. It walks through DC house loads plus battery charge current requirements for your battery bank chemistry.
Step 3: Understand the Physical Fit Constraint
WFCO publishes cutout dimensions in its cross-reference guide (verified 2026-09-23 via wfcotech.com/support/cross-reference-guide/). Same-series replacements are designed to use the same cutout:
| Series | Typical Cutout (W x L x H) | Output Range |
|---|---|---|
| WF-8500-AD (WF-8540-AD, WF-8560-AD) | 7 3/4 x 7 7/16 x 11 1/8 in | 40 and 60 A |
| WF-8700 (WF-8712, WF-8725-AD, WF-8735-AD, WF-8740-AD) | 10 3/8 x 4 to 4 1/8 x 6 to 7 in | 12 to 40 A |
| WF-8900-AD (WF-8935-AD, WF-8945-AD, WF-8955-AD) | 12 x 7 x 10 3/4 in | 35, 45, and 55 A |
| WF-9500-AD (WF-9540-AD, WF-9560-AD, WF-9580-AD) | 10 x 8 5/8 x 13 in | 40, 60, and 80 A |
Dimensions are cutout or physical dimensions from WFCO's cross-reference document. Always measure your existing opening before ordering, as individual coach installations can vary. Do not rely on series-level dimensions alone for fitment confirmation.
If your coach has a non-WFCO power center (Magnetek, Parallax, Progressive Dynamics, or another brand), WFCO's cross-reference guide includes a second-page converter chart mapping those brands to WFCO equivalents. The universal REP kits (WF-8935-AD-REP, WF-8945-AD-REP, WF-8955-AD-REP) are specifically designed for replacing non-WFCO power centers and include the converter, the DC fuse board, and required fasteners. Their footprint is 11 7/8 x 7 5/8 x 5 3/4 inches regardless of amperage variant.
The Two In-Brand WFCO Replacement Paths
Path A: Board Assembly Replacement (MBA)
If your WF-8900-AD Series power center housing is in good condition, a Main Board Assembly (MBA) replacement is the most economical upgrade. You remove the old converter module and install a new board into your existing housing. You keep the existing breaker panel, wiring, and door.
MBA parts for the WF-8900-AD series:
- WF-8935-AD-MBA: 35 amps, 7 1/16 x 9 1/2 x 3 7/8 in
- WF-8945-AD-MBA: 45 amps, 7 1/16 x 9 1/2 x 3 7/8 in
- WF-8955-AD-MBA: 55 amps, 7 1/8 x 9 1/2 x 3 3/4 in
- WF-8975-AD-MBA: 75 amps, 10 5/8 x 8 3/4 x 4 1/2 in
All WF-8900-AD-MBA assemblies include Auto-Detect technology and support both lead-acid and lithium-ion battery chemistries automatically per WFCO's manufacturer product listings, verified 2026-09-23.
This path requires that the existing housing, AC circuit breakers, and DC fuse panel are serviceable. If the housing has heat damage or corrosion at the bus connections, a full unit replacement is a better choice.
Path B: Full Unit Replacement
A full unit replacement gives you a new warranted system. WFCO offers two types:
Same-brand, same-series replacement: Order the equivalent WF-8900-AD model in your output size (WF-8935-AD, WF-8945-AD, WF-8955-AD, WF-8965-AD). These drop into the same 12 x 7 x 10 3/4 inch cutout as other WF-8900-AD units. All WF-8900-AD models include Auto-Detect technology. Verified specs from WFCO's product pages (wfcotech.com), 2026-09-23:
| Model | Output | Input | Power | Note |
|---|---|---|---|---|
| WF-8935-AD | 35 A | 105-130 VAC, 60 Hz | 600 W | Auto-Detect, 30A service |
| WF-8945-AD | 45 A | 105-130 VAC, 60 Hz | 770 W | Auto-Detect, 30A service |
| WF-8955-AD | 55 A | 105-130 VAC, 60 Hz | 940 W | Auto-Detect, 30A service |
| WF-8965-AD | 65 A | 105-130 VAC, 60 Hz | 1110 W | Auto-Detect, 30A service |
All models carry WFCO's two-year limited product warranty, per wfcotech.com/support/warranty-returns/, verified 2026-09-23.
Universal REP kits for non-WFCO enclosures: The WF-8900-AD-REP series (WF-8935-AD-REP, WF-8945-AD-REP, WF-8955-AD-REP) allow replacement of other manufacturers' power centers with a WFCO converter module plus a new DC fuse board. Per WFCO's product category page (verified 2026-09-23): "Technicians can easily remove the lower section of certain power center brands and slide in the WF-8900-AD-REP unit." These kits include Auto-Detect technology and upgrade a single-stage charger to three-stage charging in both lead-acid and lithium profiles.
The Charge Profile That Comes with Modern WFCO-AD Units
Every WF-8900-AD series unit, MBA assembly, and REP kit uses three-stage charging plus WFCO's Auto-Detect battery chemistry recognition. The base charge profile for the WF-8935 (non-AD, lead-acid) unit, verified from WFCO's own product page on 2026-09-23, is:
- Bulk (quick charge): 14.4V DC
- Absorption: 13.6V DC
- Float: 13.2V DC
The AD (Auto-Detect) variants extend this to a lithium-ion profile as well. Per WFCO's Auto-Detect technology page (wfcotech.com/auto-detect/, verified 2026-09-23): "Auto-Detect automatically selects the correct charging profiles for both lead acid and lithium iron phosphate batteries, optimizing charging and maximizing your battery life."
The WF-8955-AD-REP specifically is rated for a lithium voltage range of 13.2 to 14.6V DC (per the product listing verified in session), which fits within the absorption range most LiFePO4 battery manufacturers specify.
Note on certification: WFCO's WF-8900-AD series product sheet states the series is UL and cUL listed and FCC Class B compliant, covering the WF-8935-AD through WF-8975-AD models. That is a series-level statement from the manufacturer, so it is the certification claim we will make. If you need certification proof for a specific installation or inspection, request the listing for your exact model number from WFCO rather than relying on a series document.
The Lithium Upgrade Path: Where to Route
If you are replacing your WFCO converter specifically because you are adding a lithium battery bank, the critical questions are: which exact model do you have now, and does it already support lithium?
This pillar page does not duplicate the suffix-level analysis that answers those questions. That work lives on the dedicated detail page for the WF-8955 line, which also covers the MBA and REP paths for the 8955 specifically, with a full suffix matrix.
See: WFCO 8955 lithium replacement converter options
If you have an 8900-series model other than the 8955 (such as a WF-8935 or WF-8945) and are adding lithium, the same logic applies: the base model without the -AD suffix is lead-acid only. The -AD variant includes Auto-Detect for both chemistries. Contact WFCO technical support at [email protected] to confirm the exact lithium upgrade path for any model not in the WF-8955 range.
Also relevant: if your WFCO Auto-Detect unit is not recognizing your lithium battery correctly, see WFCO Auto-Detect not detecting lithium for troubleshooting before concluding a replacement is needed.
When to Replace vs. Troubleshoot
Not every failing WFCO unit needs a full replacement. Certain faults are component-level fixes:
Replace the MBA board instead of the full unit if: The housing and AC breakers are intact, but the converter module is not charging or the fan runs continuously without output. A failed board in a sound housing is a board swap, not a whole-unit replacement.
Replace the full unit if: The housing has heat or corrosion damage at the bus connections, the AC breaker section is damaged, or the unit is out of warranty and multiple subsystems have failed.
Troubleshoot before replacing if: The converter fan is running but the unit is not charging the battery. This symptom has several possible causes outside the converter itself, including a failed battery, a blown reverse-polarity fuse on the converter output, or a disconnected battery cable. See RV converter fan running but not charging for the diagnostic sequence before ordering a replacement.
The WFCO FAQ (verified 2026-09-23) notes that reverse protection fuses for the WF-8900 series are rated as follows (manufacturer requirement, replace only with ATO or ATC fuses of the same rating):
- WF-8935: 40A reverse protection fuse
- WF-8945: 30A, 30A (two fuses)
- WF-8955: 40A, 40A (two fuses)
- WF-8965: 20A, 20A, 20A, 20A (four fuses)
Always replace blown fuses with the same rating before concluding the converter board has failed.
Comparison: In-Brand vs. Universal Replacement
| Factor | MBA Board Swap | Same-Series New Unit | REP Universal Kit |
|---|---|---|---|
| Best for | WFCO housing in good shape | WFCO housing damaged or at end of life | Non-WFCO power center or brownout repair |
| Labor scope | Board swap inside existing housing | Full panel removal and install | Lower-section removal, kit slides in |
| Auto-Detect | Yes (8900-AD-MBA models) | Yes (all WF-8900-AD) | Yes |
| Lithium support | Yes (8900-AD-MBA models) | Yes (all WF-8900-AD) | Yes |
| WFCO warranty | Yes (2-year) | Yes (2-year) | Yes (2-year) |
| Available amperages | 35, 45, 55, 75 A | 35, 45, 55, 65 A | 35, 45, 55 A |
Amperages verified from WFCO cross-reference guide and product category page, 2026-09-23.
Frequently Asked Questions
Can I install a higher-amperage WF-8900-AD unit in the same footprint as my WF-8935?
The cutout dimensions for the WF-8935-AD, WF-8945-AD, and WF-8955-AD are all 12 x 7 x 10 3/4 inches per WFCO's cross-reference guide. They use the same physical opening. However, higher output requires that the wiring feeding the converter and leaving the DC bus can handle the added current. Do not install a 55A unit where the existing DC wiring was sized for a 35A unit without verifying wire gauge and fuse adequacy. This is a manufacturer requirement: DC branch circuit fuse ratings are set to protect the wire gauge in use, not just the device.
My power center is a Magnetek or Parallax, not a WFCO. Can I still use a WFCO replacement?
Yes. The WF-8900-AD-REP kits are specifically designed for this scenario. WFCO's product page states the kit allows easy upgrades of existing power centers, and WFCO's cross-reference guide (verified 2026-09-23) includes a chart mapping Magnetek, Parallax, Progressive Dynamics, and IOTA models to WFCO equivalent REP kits. The REP kit includes the converter, DC fuse board, and required fasteners. The REP series is available in 35, 45, and 55A output.
Does every WFCO converter come with a warranty?
WFCO extends a Two-Year Limited Product Warranty on its products, per the warranty page at wfcotech.com/support/warranty-returns/, verified 2026-09-23. The warranty applies only to products purchased from WFCO authorized sellers. WFCO reserves the right to reject claims for products purchased from unauthorized sellers, including unauthorized internet sites and marketplace storefronts. The warranty is limited to the repair or replacement, at WFCO's discretion, of defective parts or defective assembly.
Can I do an MBA board swap myself or does it require a technician?
WFCO does not publish a specific technician-only requirement for MBA board swaps on their public pages. However, the work involves disconnecting 12V DC wiring and AC mains connections from an active panel. Turn off shore power and the main AC breaker before opening the unit. If you are not comfortable identifying and safely disconnecting live wiring inside a power center, hire a qualified RV technician. Incorrect installation can damage the new board, void the warranty, or create a shock or fire risk.
Where is the model number on my WFCO power center?
Per WFCO's FAQ (verified 2026-09-23): The WF-8500, WF-8700, WF-8900, and WF-9900 series show the model number on the inside front panel, next to the breakers. Open the front door of the power center and look for the label on the front panel between the breakers and fuses. Write down or photograph the exact string including any suffix letters.
What if my WFCO unit is older and not in the current lineup?
Older WFCO units (WF-8800, WF-8700 brown-format, early WF-8900) may not have a direct same-model equivalent in the current catalog. Use the WFCO cross-reference guide at wfcotech.com/support/cross-reference-guide/ to find the current-generation equivalent. The guide maps legacy models to current WFCO products by footprint and amperage. If the guide does not resolve your model, contact WFCO technical support directly at [email protected] or by phone at 574-294-8997.
Sources
- WFCO Cross-Reference Guide (2025 edition) Manufacturer cross-reference guide landing page. Confirms source document at wfcotech.com/wp-content/uploads/2025/09/NEW-CrossRef-Sheet_25.pdf. Verified live 2026-09-23 via browser. Authority tier: manufacturer support document.
- WFCO Cross-Reference PDF (NEW-CrossRef-Sheet_25.pdf) Two-page manufacturer cross-reference document. Source for all power center series cutout dimensions: WF-8540-AD/WF-8560-AD (7 3/4 x 7 7/16 x 11 1/8 in), WF-8712/WF-8725-AD/WF-8735-AD/WF-8740-AD (10 3/8 x 4 to 4 1/8 x 6 to 7 in), WF-8935-AD/WF-8945-AD/WF-8955-AD (12 x 7 x 10 3/4 in), WF-9540-AD/WF-9560-AD/WF-9580-AD (10 x 8 5/8 x 13 in). Also confirms MBA dimensions (WF-8935-AD-MBA 7 1/16 x 9 1/2 x 3 7/8 in, WF-8945-AD-MBA 7 1/16 x 9 1/2 x 3 7/8 in, WF-8955-AD-MBA 7 1/8 x 9 1/2 x 3 3/4 in, WF-8975-AD-MBA 10 5/8 x 8 3/4 x 4 1/2 in) and REP kit dimensions (11 7/8 x 7 5/8 x 5 3/4 in for all three amperages). PDF opened in browser 2026-09-23. Authority tier: manufacturer document.
- WFCO WF-8900-AD Series Power Center Category Page Manufacturer product category page. Source for WF-8935-AD (35A, 600W, $281.99), WF-8945-AD (45A, 770W, $294.99), WF-8955-AD (55A, 940W, $309.99), WF-8965-AD (65A, 1110W, $472.99). All units: 105-130 V ac, 60 Hz input. Describes Auto-Detect as industry exclusive, patent-pending technology available in 35, 45, 55, 65, and 75 amps. Verified live 2026-09-23 via browser. Authority tier: manufacturer product page.
- WFCO WF-8935 Power Center Spec Page Manufacturer product specification page for the WF-8935 (base, non-AD model). Source for: 3-stage charging profile (Bulk 14.4V DC, Absorption 13.6V DC, Float 13.2V DC), certifications (FCC, UL and cUL Listed), input 105-130 VAC 60Hz, output 35A, continuous output power 475W, input power 600W, AC circuits 10 (Main and 9 branch), DC circuits 11 (2 at 30A max, 9 at 20A max), dimensions 14.17 x 11.81 x 8.5 inch, weight 6.13 lbs. Verified live 2026-09-23 via browser. Authority tier: manufacturer product page.
- WFCO WF-8540-AD-MBA Power Center Page Manufacturer product page for WF-8540-AD-MBA. Source for: 40A DC output, 685W, 105-130 V ac 60 Hz, Auto-Detect technology description (microprocessor-driven, recognizes lithium-ion and lead-acid, automatically adjusts charging profile, multi-stage charging with current monitoring). Verified live 2026-09-23 via browser. Authority tier: manufacturer product page.
- WFCO FAQ: General and Electric Tabs Manufacturer FAQ page. Source for: (1) model number location by series: WF-8500/WF-8700/WF-8900/WF-9900 show model number on inside front panel next to breakers; WF-8800/WF-9800/WF-6800/WF-5100 show on top label. (2) Reverse protection fuse ratings for WF-8900 series: WF-8935 = 40A; WF-8945 = 30A, 30A; WF-8955 = 40A, 40A; WF-8965 = 20A x 4. (3) DC fuse sizes determined by manufacturer. Verified live 2026-09-23 via browser. Authority tier: manufacturer FAQ.
- WFCO Warranty Service and Returns Page Manufacturer warranty page. Source for: Two-Year Limited Product Warranty, effective from purchase date or date of delivery. Warranty applies only to products purchased from authorized sellers. Warranty limited to repair or replacement of defective parts or defective assembly at WFCO's discretion. Verified live 2026-09-23 via browser. Authority tier: manufacturer warranty statement.
- WFCO Auto-Detect Technology Page Manufacturer technology page for Auto-Detect. Source for: Auto-Detect automatically selects correct charging profiles for both lead acid and lithium iron phosphate batteries. Patent-pending intelligent battery detection system. Lets users change between lead acid and LiFePO4 batteries without manual reconfiguration. Verified live 2026-09-23 via browser. Authority tier: manufacturer product technology page.
- WFCO WF-8900-AD-REP Converter Replacement Kit Category Manufacturer category page for the WF-8900-AD-REP series. Source for: REP kits available in 35, 45, and 55A; include converter, DC fuse board, and required fasteners; designed for replacing other manufacturers' power centers; upgrades single-stage charger to three-stage charging; includes Auto-Detect for lead-acid and lithium-ion. Retrieved via search snippet 2026-09-23. Authority tier: manufacturer product page.
- WFCO Power Centers Category Page Manufacturer category page listing all four active Power Center series: WF-8500-AD Series, WF-8700-AD Series, WF-8900-AD Series, WF-9500-AD Series. Verified live 2026-09-23 via browser. Authority tier: manufacturer product catalog.
- WFCO WF-8900-AD Series Product Sheet WFCO manufacturer product sheet for the WF-8900-AD series. Proves per-model output current (35A/32.5A, 45A/41.5A, 55A/50A, 65A/60A, 75A/70A lead-acid vs lithium), input 105-130V AC 60 Hz, voltage output 13.2-14.4V DC lead acid and 13.6-14.6V DC lithium, bulk charge 14.4V DC lead acid and 14.6V DC lithium, outer dimensions 12 in W x 7 in L x 10 3/4 in H, and the series-level statement that the units are UL and cUL listed and FCC Class B compliant. Verified live 2026-09-23 (site refuses scripted requests; fetched in a real browser session). Authority tier: manufacturer product sheet.
Published 2026-09-23. Electrical specifications are model-specific: confirm every figure against the manual for your exact equipment before acting on it.