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Tekmar 070 / 071 Outdoor & Universal 10k Ohm NTC Thermistor Temperature Sensor for Boiler Reset Controls Engineering Diagram
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SPECFOUNDRY SKU: SF-HVC-108 · BRAND REF: Tekmar / Watts

Tekmar 070 / 071 Outdoor & Universal 10k Ohm NTC Thermistor Temperature Sensor for Boiler Reset Controls

Stamped Casting / OEM Numbers: 070 071 TEK-070 TEK-071 TH-DS-PAIR 10K-NTC-TYPE2

Compatible Units: Tekmar 256, 260, 261, 279, 356, 360, 400 Series Outdoor Reset Controls & Lochinvar / Viessmann / Triangle Tube Boilers

Critical Dimensions & Spec: 10,000 Ohm @ 77°F (25°C) Type-2 NTC thermistor; UV-resistant gray polycarbonate outdoor sun-shield enclosure; 1/2" conduit knockout

$64.99
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Pre-Order Dimensional Verification Checklist

OEM Cross-Reference & Stamped Casting Number Table

Use this cross-reference table to confirm that the number stamped or printed on your original hardware or circuit board corresponds to SpecFoundry SKU SF-HVC-108:

Stamped / OEM Part Number Manufacturer / System Brand Compatible Models & Years SpecFoundry Replacement SKU
070Tekmar / WattsTekmar 256, 260, 261, 279, 356, 360, 400 Series Outdoor Reset Controls & Lochinvar / Viessmann / Triangle Tube BoilersDirect Match (SF-HVC-108)
071Tekmar / WattsTekmar 256, 260, 261, 279, 356, 360, 400 Series Outdoor Reset Controls & Lochinvar / Viessmann / Triangle Tube BoilersDirect Match (SF-HVC-108)
TEK-070Tekmar / WattsTekmar 256, 260, 261, 279, 356, 360, 400 Series Outdoor Reset Controls & Lochinvar / Viessmann / Triangle Tube BoilersDirect Match (SF-HVC-108)
TEK-071Tekmar / WattsTekmar 256, 260, 261, 279, 356, 360, 400 Series Outdoor Reset Controls & Lochinvar / Viessmann / Triangle Tube BoilersDirect Match (SF-HVC-108)
TH-DS-PAIRTekmar / WattsTekmar 256, 260, 261, 279, 356, 360, 400 Series Outdoor Reset Controls & Lochinvar / Viessmann / Triangle Tube BoilersDirect Match (SF-HVC-108)
10K-NTC-TYPE2Tekmar / WattsTekmar 256, 260, 261, 279, 356, 360, 400 Series Outdoor Reset Controls & Lochinvar / Viessmann / Triangle Tube BoilersDirect Match (SF-HVC-108)

Common Failure Symptoms Solved by SF-HVC-108

Technicians and property owners typically replace 070 when experiencing one or more of the following failure modes:

  • Boiler outdoor reset controller flashing 'Out' or 'Sen' open/shorted sensor error
  • Boiler firing to 180°F in mild weather because outdoor thermistor drifted out of calibration
  • Water intrusion inside cracked outdoor sensor housing on north wall

Step-by-Step Dimensional Verification & Installation Notes

Disconnect 2-wire 18 AWG twist-pair at sensor terminals and measure resistance with a multimeter: should read 10,000 ohms at 77°F, 19,900 ohms at 50°F, and 32,650 ohms at 32°F. Mount on a north-facing wall away from dryer/boiler vents.

Related Technical Guide: Taco 571-2 vs. Honeywell V8043E Zone Valve Powerheads, B&G Couplers & Boiler Cross-Reference →

Frequently Asked Technical Questions (070)

Where is the casting or OEM part number (070 / 071 / TEK-070) stamped on this part?

On Tekmar / Watts assemblies, look for the stamped or die-cast numbers (070, 071, TEK-070, TEK-071, TH-DS-PAIR, 10K-NTC-TYPE2) on the underside of the metal housing, along the link arm, on the stainless hinge track, or printed on the circuit board/valve label. Note that casting numbers identify the housing casting, so always confirm critical dimensions (10,000 Ohm @ 77°F (25°C) Type-2 NTC thermistor; UV-resistant gray polycarbonate outdoor sun-shield enclosure; 1/2" conduit knockout) as well.

Does SpecFoundry SKU SF-HVC-108 directly replace OEM part 070 (070, 071, TEK-070, TEK-071, TH-DS-PAIR, 10K-NTC-TYPE2)?

Yes. SF-HVC-108 is verified to match the mounting footprint, electrical/mechanical ratings, and dimensional envelope of Tekmar / Watts 070, 071, TEK-070, TEK-071, TH-DS-PAIR, 10K-NTC-TYPE2 used on Tekmar 256, 260, 261, 279, 356, 360, 400 Series Outdoor Reset Controls & Lochinvar / Viessmann / Triangle Tube Boilers.

What measurements should I verify before ordering SF-HVC-108?

Before ordering, verify: (1) Stamped or OEM code matches one of 070, 071, TEK-070, TEK-071, TH-DS-PAIR, 10K-NTC-TYPE2; (2) Dimensional spec matches: 10,000 Ohm @ 77°F (25°C) Type-2 NTC thermistor; UV-resistant gray polycarbonate outdoor sun-shield enclosure; 1/2" conduit knockout; and (3) Application matches: Tekmar 256, 260, 261, 279, 356, 360, 400 Series Outdoor Reset Controls & Lochinvar / Viessmann / Triangle Tube Boilers.

How fast does SF-HVC-108 ship and what payment methods are accepted?

SF-HVC-108 ships within 1–2 business days from our US warehouse network. Flat-rate US Ground shipping is $8.95, or FREE on orders of $150+. You can check out online immediately via PayPal, Venmo, Credit/Debit Card, or request an Instant Card Payment Link / Net-30 Commercial PO Invoice.

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