Buy the T104M only when a qualified electrician has confirmed that you need a T104-family mechanism and can retain a suitable existing enclosure. If the complete box needs replacing, the package matters: plain T104 has an indoor metal enclosure, while T104R includes an outdoor Type 3R metal enclosure. An outdoor equipment pad needs the appropriate outdoor enclosure, not simply a listing with “T104” in its name. These identities come from Intermatic’s model guide and T104R specifications .
This is a researched purchase guide, not an installation procedure or a hands-on timer test. A stopped dial, low circulation or a pump that fails to start does not establish which component has failed. Have the electrical assessment and installation performed by a qualified electrician. Do not open electrical covers or test terminals to complete this worksheet.
Replacement-package matrix
The family number identifies the electrical model; its ending identifies the package or an added feature. Read the complete designation, including numbers after the enclosure suffix.
| Exact model or ending | Enclosure supplied | Purchase implication |
|---|---|---|
| T104M | None, mechanism only | Consider when the electrician approves retaining the existing enclosure and confirms the mechanism fit. |
| T104 | Gray indoor metal | A complete indoor package does not answer an outdoor-enclosure requirement. |
| T104R | Gray outdoor Type 3R metal | A complete outdoor package to assess when both mechanism and box need replacement. |
| R3 | Beige outdoor metal | Color and enclosure variant; retain the full model when requesting a replacement. |
| P or P3 | Outdoor plastic, gray or beige respectively | A different enclosure material, not a different clock-input family. |
| R201, P201 or M201 | Package includes a fireman’s switch | Identify required heater protection before considering a package without this feature. |
The suffix identities are from Intermatic’s T100 model guide . Its pool-pump selection guidance specifies appropriate outdoor Type 3R enclosures for pool and spa applications. Enclosure choice still depends on the actual installation.
Intermatic says the T104M fits most Intermatic enclosures . “Most” is not confirmation for an unidentified box, another manufacturer’s enclosure or one that needs repair. Buying a mechanism also leaves the enclosure assessment unresolved; a new mechanism does not replace a damaged box or door.
Keep clock input separate from pump-load ratings
Four specification fields answer different questions. Copy all four into the replacement enquiry instead of reducing the timer to “240 V, 40 A.”
| T104M specification | Manufacturer value | What it establishes |
|---|---|---|
| Clock input | 208-277 VAC, 60 Hz | The supply requirement for the timer mechanism. |
| Switch type | DPST, double-pole single-throw | The switching arrangement, which the electrician must match to the application. |
| Inductive contact rating | 40 A, 120-277 VAC | A switched-load rating; it does not replace the motor-load check below. |
| Motor-load entries | 2 HP, 24 FLA at 120 VAC; 5 HP, 28 FLA at 240 VAC | Separate motor-load limits at the stated load voltages, not alternative clock-input voltages. |
These are the entries in the T104M specifications and its manufacturer technical data sheet . FLA means full-load amperes. Do not treat a headline contact rating as proof that every residential pump fits: Intermatic requires matching the motor to the exact model’s load ratings .
In particular, the 120 VAC motor-load entry does not make the T104M clock a 120 V clock. Intermatic’s model guide distinguishes 120 V clock-motor families from 208-277 V families and identifies T104-50 as a 50 Hz exception. Neither a familiar dial nor a similar box establishes interchangeability. If the installed designation is T101, T103, T104-50 or unreadable, stop using this three-package comparison as a replacement recommendation.
Identification worksheet for the electrician
Use existing service paperwork, the equipment manuals and externally readable labels. Leave an unknown field marked “unknown” in your own record rather than guessing. Obtain professional identification if a label is inaccessible without opening electrical equipment.
| Field to record | Record from documents or readable labels | Confirmation needed before ordering |
|---|---|---|
| Installed timer identity | Full model, suffix and any 201 or -50 ending |
Is this the exact timer family being replaced, and has replacement been established? |
| Existing enclosure | Manufacturer, model and recorded indoor/outdoor rating | Can it safely remain, and does the proposed mechanism fit? |
| Clock supply | Documented voltage and frequency, or unknown | Does the actual supply meet the proposed clock-input specification? |
| Controlled equipment | Exact pump model and any connected controller | Is this timer’s switching arrangement appropriate for the system? |
| Pump motor rating | Nameplate voltage, HP and amperes as printed | Does the applicable motor-load entry cover the actual load? |
| Heater protection | Heater model and any documented fireman’s switch or interlock | What protection must remain in the replacement configuration? |
| Requested purchase | Mechanism only or complete timer and enclosure | Does the seller’s exact model supply the approved package? |
Ask for the approved replacement designation in writing. Keep it with the receipt and service record. This avoids a future owner mistaking the enclosure’s old model label for proof of a later mechanism’s identity.
Which package earns a purchase?
T104M is the focused purchase when only the mechanism needs replacement and the enclosure, supply, load and protection checks pass. The verified Intermatic T104M Amazon listing is for the mechanism-only model. Before checkout, confirm the selected offer still says T104M and does not substitute a clock motor, tripper set or complete boxed timer. No enclosure is included in this recommendation.
T104R is the complete outdoor-metal package to discuss when the box also needs replacement. Its manufacturer record identifies an indoor/outdoor Type 3R metal enclosure. We have not verified an exact Amazon buying destination for that complete package, so the T104M button is not a route to buy T104R. Ask the electrician to identify the full approved outdoor model, including any heater-protection requirement, before shopping for it.
Plain T104 is the indoor-metal package. Do not choose it for an exposed pool equipment pad merely because it resembles the existing timer. Nor should you replace a model ending in 201 with bare T104M on the assumption that the extra digits are cosmetic. Have the heater’s required protection assessed and preserved.
The T104M’s mechanical schedule uses a 24-hour dial with a minimum one-hour ON/OFF interval; one ON and one OFF tripper are supplied. If the required schedule needs shorter intervals or other controls, have the electrician select a suitable alternative before buying this mechanism.
The trade-off is scope, not a proven saving: a mechanism purchase retains the existing box, while a complete package supplies a box too. We have no current installed-cost comparison, labor quotation or reliability test showing which costs less over ownership.
When to buy nothing yet
Wait if replacement has not been established, any worksheet identity is unknown, or the proposed package omits a required enclosure or heater feature. A timer purchase does not resolve a hydraulic problem. For weak circulation, the flow-and-filter-gauge decision map separates observations without treating pressure as proof of timer failure.
Keep related purchases separate. A salt-cell warning needs the controller and cell checks in our AquaRite replacement guide ; it does not establish that an external circulation timer needs replacing.
After a legitimate repair, retain the documented circulation schedule and verify the connected equipment under its own instructions. If a tablet feeder depends on that circulation, our feeder-verification guide explains why a changed run schedule needs fresh water-result checks. This article does not prescribe universal pump hours or claim energy savings.
Research method and limits
On October 1, 2026, we reconciled Intermatic’s model-suffix guidance and pool-pump selection advice with the named T104M and T104R product specifications. The preparation research also checked the T104M manufacturer data sheet dated May 18, 2026. The worksheet is our synthesis of the separate identification and rating checks, not a manufacturer installation checklist.
We did not test a timer, assess an enclosure, measure voltage, diagnose a pump or verify an individual heater configuration. The US Amazon T104M model and buying destination were checked on October 1, 2026; price, availability, delivery and seller terms can change. Exact equipment manuals and the qualified electrician’s assessment control installation suitability.