Ensure your Dri-Eaz HydroSensor stays field-ready with the Thumb Screw Replacement (Part #03-00152), designed to fit both the F245 and F251 HydroSensor models. This is a genuine Dri-Eaz replacement part: a black plastic thumb knob that tightens by hand, with no tools needed.
What It Does
Dri-Eaz lists part 03-00152 in the HydroSensor parts breakdown as the "Slide Knob Assy – 1/4-20 x 3/8 BLK", one per unit.
On the HydroSensor II (F251) the knob locks the collapsible shaft. The owner's manual describes it: loosen the black plastic knob, push it down and around the S-shaped slot, then tighten the knob to lock the shaft in position. If the knob is cracked, stripped or missing, the shaft will not hold its length and the probe becomes awkward to use.
The same part appears on the HydroSensor I (F245) parts breakdown. Dri-Eaz does not describe its function on the fixed-shaft F245, so check the parts breakdown against your probe before ordering.
Key Features
- Genuine Dri-Eaz Replacement Part – Designed specifically for the F245 and F251 HydroSensors.
- Part Number: 03-00152 – Exact match for original equipment.
- Tool-Free Installation – Thumb screw design for easy tightening and adjustments on the go.
- Durable and Reliable – Built for tough restoration environments and frequent use.
- Keeps the probe usable – On the HydroSensor II a secure knob holds the shaft at the length you need, so you can keep the tips square on the carpet for a consistent reading.
Compatible With
Specifications
| Brand | Dri-Eaz (Legend Brands) |
| Dri-Eaz part number | 03-00152 |
| Description (Dri-Eaz) | Slide Knob Assy – 1/4-20 x 3/8, black |
| Size | 1/4-20 x 3/8 (as listed by Dri-Eaz) |
| Quantity per HydroSensor | 1 |
| Fits | HydroSensor I (F245), HydroSensor II (F251) |
| Pack | Each |
| CCW SKU | F0300152 |
Fitting
- Collapse the shaft (HydroSensor II) and hold the tube so it cannot slide while the knob is off.
- Unscrew the old knob by hand and check the thread it screws into for damage.
- Thread the new knob in by hand. Do not force it; a cross-threaded knob will not lock the shaft.
- Extend the shaft, move the knob around the S-shaped slot and tighten it. Check the shaft holds before you use the probe.
Frequently Asked Questions
My HydroSensor II shaft keeps sliding. Is it the knob?
Usually. If the knob turns but does not tighten, or the plastic is cracked, replace it. If the knob tightens but the shaft still slides, the tube or slot may be worn; send us a photo before ordering.
Can I use a hardware-store thumb screw instead?
Dri-Eaz lists the thread as 1/4-20. A generic knob may fit, but length matters: too long can bind or damage the inner tube. The genuine part avoids that guesswork.
Does this fix a probe that is not lighting up?
No. A dead light is usually the 9 V battery or dirty tips. See the care section on the HydroSensor II page.
Ideal For
Restoration professionals, flood remediation, carpet cleaning, and water damage contractors.
Documents
- Parts Breakdown — F245 and F251 HydroSensors, all variants. Use it to confirm the part before you order.
- Owner’s Manual — HydroSensor I & II, models F245 and F251.
Related Products
- Dri-Eaz HydroSensor replacement handle
- Dri-Eaz HydroSensor I Moisture Probe (F245)
- Dri-Eaz HydroSensor II Moisture Probe (F251)
- Dri-Eaz Moisture Meters
Not sure which part your HydroSensor needs? Send us the model and a photo of the damaged part and we will confirm it before you order.
