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BP501G1 MS50U Control 1.0/4.0kW Flow Thru Heater X300732 - Bubbles Supply

BP501G1 MS50U Control 1.0/4.0kW Flow Thru Heater X300732

Part #: X300732

$1455.69
In stock — ships today
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Also replaces

BP501G1
1-year warrantySame-day ship before 3pm CTPerfect Fit Guarantee30-day returns

About this heater

The BP501G1 MS50U Control 1.0/4.0kW Flow Thru Heater X300732 is a genuine Master Spa replacement control system designed for compatible Master Spas hot tubs. This OEM control pack features a flow-through heater configuration with 1.0/4.0kW heating capacity and includes third sensor capability for enhanced temperature monitoring and safety. The MS50U system effectively resolves common heating issues including HH (high heat) and OH (overheat) error codes.

At Bubbles Supply, we guarantee this Master Spa control system provides an exact fit for your spa's heating requirements. Every BP501G1 ships same-day when ordered before our cutoff time and comes backed by our comprehensive 1-year warranty for complete peace of mind. This genuine OEM replacement ensures reliable heating performance and proper system integration. Verify your existing control part number matches BP501G1 before installation to ensure proper compatibility with your Master Spa's electrical and plumbing connections.

Exact part number

X300732

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Also known as / Replaces

This part replaces or is interchangeable with:

  • BP501G1
  • Master Spa flow-through heater assembly
  • MS50U control pack
  • MS50U heater control system

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

Technical specifications

Voltage
240V
Port type
Flow-through (inline)

Plumbing notes

  • Port type: Flow-through (inline)

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:

  • HH (high heat) error code won't clear
  • OH (overheat) error code on display
  • Spa not heating or heating intermittently
  • Control system failing to regulate water temperature
  • Third sensor fault or temperature monitoring errors
  • Spa tripping breaker due to heater fault

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

Before you buy — quick checklist

  • Confirm your existing control pack part number is BP501G1 — verify on the label of the unit being replaced
  • Confirm your spa is a compatible Master Spa model before ordering
  • Verify your spa runs on 240V service
  • Check whether your current system uses the third sensor connection — this unit includes third sensor capability
  • Inspect existing plumbing connections and union fittings for condition before reinstalling
  • Note any active error codes on your spa display to confirm a heater/control fault is the root cause

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

Install difficulty: Hard — Technician recommendedTypically 60-120 minutes

Warranty

1 year 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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