Rheem Marathon Thermal Storage Tank Series

Marathon Thermal Storage Tank

Marathon® thermal storage tanks feature a lifetime limited tank warranty and a 6-year limited parts warranty*

Designed for Alternative Energy Applications

  • Specifically designed for installation as a thermal storage tank
  • Backup electrical element provides 40 gallons or more of heated water
  • Large water connections for lower pressure drop
Built to Last!
  • Seamless, blow-molded, polybutene tank – impervious to rust and corrosion
  • Titanium sheath elements for superior resistance to lime build-up
  • Multiple layers of filament wound fiberglass give the tank unmatched strength
  • Tough molded polyethylene outer shell resists dents and scratches
Designed for Easy installation
  • Lightweight
  • Water port fittings located at front of storage tank for convenient access
  • Full port, full flow brass drain valve for fast draining
  • Factory installed temperature and pressure relief valve and vacuum relief valve
  • Thermally fused element provides protection against “dry-firing”
  • Bowl shaped bottom allows for complete sediment removal
  • Recessed drain valve is out of the way of brooms and scrubbers

  50 MTS50200
  85 MTS85200
  105 MTS105200
  85 MTS85245

105 MTS105245

85 MTS85345

105 MTS105345

85 CMTS852000
105 CMTS105200

Available in Canada

  • 50, 85 and 105 gallon capacities, 2 port and 3 port configurations
  • Specifically designed for installation as a thermal storage tank
  • Large water connections
  • Tank – impervious to rust, corrosion


Marathon Thermal Storage Tank
Brochure (US and Canada)
Specification Sheet (US and Canada)
Use and Care Instructions (French)
Use and Care Manual (US and Canada)
Use and Care Manual (US and Canada)


United States
Lifetime Limited Tank Warranty
6-Year Limited Parts Warranty

Lifetime Limited Tank Warranty
6-Year Limited Parts Warranty

KwikComfort® Financing can help make your purchase even easier.
Rheem makes it easy to find a financing option that works for you! With many options and benefits available, KwikComfort Financing is the best way to get the home comfort you need without the wait.

  • Applications made easyWe'll help you avoid lengthy contracts, headaches and hassles.
  • Kwik credit decisionsYou'll get an answer to your application within minutes.
  • Fast credit for the futureFinance your Rheem equipment and anything you want to add later.
  • Reduced interest/fixed paymentsGet low interest and fixed monthly payments until the purchase is paid.
  • Minimum monthly paymentTake advantage of convenient monthly payments that fit your budget.
  • Deferred interest/no interestEnjoy interest-free payments as long as the balance is paid by the due date.
  • y_2018, m_6, d_18, h_23
  • bvseo_bulk, prod_bvrr, vn_bulk_2.0.8
  • cp_1, bvpage1
  • co_hasreviews, tv_0, tr_7
  • loc_en_US, sid_be87f173-3224-430d-945e-326e446ddc19, prod, sort_[SortEntry(order=RELEVANCE, direction=DESCENDING)]
  • clientName_rheem