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Tecmark Pressure Switch 3903 - Bubbles Supply

Tecmark Pressure Switch 3903

Part #: 3903

$50.19
In stock — ships today
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1-year warrantySame-day ship before 3pm CTPerfect Fit Guarantee30-day returns

About this pressure switch

The Tecmark 3903 pressure switch is a reliable SPST (single pole, single throw) replacement part designed for spa and hot tub chemical dosing systems. This precision switch operates at 1-5 PSI pressure range with 1 amp capacity and features standard 1/8" NPT threading for universal compatibility with most spa chemical feeders and sanitizer systems.

Built to Tecmark's exacting OEM standards, this pressure switch ensures your spa's chemical automation works flawlessly. At Bubbles Supply, we guarantee this is the exact fit for your system and back it with our 1-year warranty. Most orders ship same day from our Canadian warehouse. Before installation, verify your existing switch's pressure range and electrical specifications match the 1-5 PSI and 1 amp ratings to ensure proper chemical system operation.

Exact part number

3903

Save this for ordering or warranty claims

Also known as / Replaces

This part replaces or is interchangeable with:

  • pressure switch chemical feeder
  • spa sanitizer pressure switch
  • SPST pressure switch 1-5 PSI
  • Tecmark 3903

Looking for an older part number? Check our supersession lookup tool

Technical specifications

Amperage
1A
Port type
1/8" NPT

Plumbing notes

  • Port type: 1/8" NPT

Need help measuring? Email hello@bubblessupply.com with a photo of your existing plumbing.

Common symptoms this part fixes

If your spa is showing any of these signs, this part is likely your fix:

  • Chemical feeder not activating when pump runs
  • Sanitizer system cycling on and off erratically
  • Chlorine or bromine not being dispensed despite pump running
  • Chemical dosing pump runs continuously without shutting off
  • Spa water chemistry imbalanced due to failed automation trigger

Not sure if this is your problem? Try our diagnostic centre or .

Before you buy — quick checklist

  • Confirm your existing pressure switch is rated 1-5 PSI — do not substitute a different pressure range
  • Verify your chemical feeder circuit is 1 amp or under before installing
  • Check that your chemical feeder or sanitizer system uses 1/8" NPT port threading
  • Confirm SPST switch configuration matches your system wiring (two terminals, not three)
  • Inspect the port on your feeder for thread damage or corrosion before swapping the switch

Reading the checklist now prevents 90% of returns. Worth the 60 seconds.

Install difficulty: Medium — Some experience neededTypically 20-45 minutes

What's in the box

  • Tecmark 3903 pressure switch
  • Wire leads

If your order is missing any items listed above, contact hello@bubblessupply.com within 48 hours of delivery.

Warranty

1 year manufacturer warranty against defects

Covers manufacturing defects. Does not cover improper installation, normal wear, or accidental damage.

Warranty claims: warranty@bubblessupply.com

Perfect Fit Guarantee

Ordered with our help and the part doesn't fit? Contact us before installation. We'll resolve it with an exchange, replacement recommendation, or return approval.

Learn about our Perfect Fit Guarantee →

Shipping

We ship across the US and Canada. US orders ship from our US warehouse to US customers; Canadian orders ship from our Canadian warehouse to Canadian customers — no cross-border shipping, no surprise duties. In-stock orders placed before 3pm CT ship same day. Standard shipping $9.95 flat rate. Free shipping on orders over $200. Express options available at checkout.

Returns

30-day hassle-free returns on unused parts in original packaging. Contact us before returning to receive your RMA number.

Frequently asked questions

Check the Compatibility section above to confirm fitment for your spa brand and model. If your model is not listed, use our fitment selector at /pages/find-my-part or ask our parts AI for a personalized recommendation.

In-stock orders placed before 3pm CT ship the same day. You will receive tracking information by email as soon as your order ships.

We accept returns within 30 days of delivery for unused items in original packaging. Email returns@bubblessupply.com with your order number to start a return. Installed electrical parts cannot be returned for safety reasons.

Yes, all new parts come with a 1-year warranty against manufacturing defects. Warranty does not cover damage from improper installation or normal wear and tear.

Customer reviews

AI Fitment Assistant

Tell us your spa model and we will confirm this part fits before you buy.

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