# Ungrounded Outlet Fixes in Boston > Fixing ungrounded outlets in older Boston-area homes: two-prong and false three-prong outlets tested, grounded circuits run, GFCI options and bonding checked. URL: https://deckerbostonknobandtube.com/ungrounded-outlet-upgrade/ [Decker Boston Knob and Tube](https://deckerbostonknobandtube.com/) arranges ungrounded outlet fixes across Boston and nearby cities, carried out by licensed and insured electricians who test what is behind each outlet before deciding what to change. A two-prong outlet, or a three-prong outlet with nothing on its ground screw, is a sign the circuit has no equipment grounding conductor. In a pre-war house that usually means knob and tube or early two-wire cable. The right fix depends on which, because a device change fixes some circuits and only a new circuit fixes others. Where the circuits turn out to be knob and tube, the job becomes a [partial knob and tube replacement](https://deckerbostonknobandtube.com/partial-knob-and-tube-replacement/). ## What happens on the first visit The first visit sorts outlets into groups by circuit. Testing a few outlets tells you little; knowing which circuit each one is on, and what that circuit is made of, tells you what the fix will be. ### At the outlet The electrician tests each suspect outlet, then removes the cover and looks. Is there a ground wire in the box at all? Is it connected? Is there a jumper from the neutral terminal to the ground screw? Is the box metal, and if so, is it connected to anything? Old boxes are often too shallow for a modern device with a ground, which matters when the fix is a new receptacle. ### At the panel and the service Then the circuits are traced back. The panel shows which circuits have grounding conductors and which don’t, and the service shows how the whole system is grounded: the grounding electrode connection, the bonding of the water and gas piping, and the main bonding inside the panel. A circuit can only be as well grounded as the service it comes from, so this check happens even when the problem looked like one outlet. The [knob and tube inspection](https://deckerbostonknobandtube.com/knob-and-tube-inspection/) covers the tracing in more detail. ### What you get back You get a list of outlets by circuit, what each circuit is made of, and a recommended fix for each one, with the circuits that need replacing separated from the ones that can be dealt with at the box. ## Why old outlets have no ground Knob and tube carries two conductors, a hot and a neutral, on separate porcelain supports. There is no third wire, because the system was designed before equipment grounding was part of house wiring. It was built that way, so the missing ground isn’t damage, and on its own it doesn’t show that a circuit is failing. The [guide to identifying knob and tube](https://deckerbostonknobandtube.com/guide/how-to-identify-knob-and-tube-wiring/) shows what it looks like. Later wiring did not always fix it. Early cloth-sheathed cable may have only two conductors, and early armored cable may rely on its spiral metal jacket as the only ground path, which is an unreliable one. The [cloth wiring replacement](https://deckerbostonknobandtube.com/cloth-wiring-replacement/) page covers both. ### What a ground actually does An equipment grounding conductor gives fault current a low-resistance path back to the panel. If a hot wire touches the metal case of a toaster, a lamp or a washing machine, current rushes down that path and trips the breaker in a fraction of a second. Without it, the case can stay energized until someone touches it and becomes the path instead. That is the shock concern behind ungrounded circuits. ### Why a three-prong outlet proves nothing Where an owner swapped two-prong outlets for three-prong ones so modern plugs would fit, the cover looks current but the ground hole leads nowhere. The shape of the face tells you which plugs fit and nothing more: not whether a grounding conductor reaches the box, not whether the run is later cable or knob and tube, and not whether a jumper is fooling the tester. The [mixed wiring guide](https://deckerbostonknobandtube.com/guide/knob-and-tube-mixed-with-romex/) explains how new outlets end up on old circuits. ## How each kind of circuit gets fixed The fix follows the circuit, not the outlet. Three cases cover most houses. ### Knob and tube circuits: replace the circuit Knob and tube has no grounding means anywhere along the run, and Massachusetts deletes NEC 250.130(C), the subsection that sets out ways of retrofitting a ground connection for existing outlets. Giving those outlets a real ground therefore means running new grounded cable from the panel, which is a circuit replacement. Since the openings are being made anyway, it is usually the moment to replace the rest of that circuit’s knob and tube too. ### Sound later two-wire cable: ground-fault protection or new cable Where the circuit is later two-wire cable in good condition, the options widen. A new grounded cable gives a true ground. Ground-fault protection at the first outlet or the breaker cuts power when current leaks to ground, which protects people without supplying a ground for equipment. Because of the Massachusetts deletion of 250.130(C), any keep-and-protect plan is confirmed with the inspector before work starts. The [GFCI and AFCI guide](https://deckerbostonknobandtube.com/guide/gfci-and-afci-on-knob-and-tube/) explains what each device does on old circuits. ### Kitchens, baths and appliance circuits Some locations need ground-fault protection regardless. Massachusetts requires it for receptacles within six feet of the top inside edge of a sink bowl, or inside a cabinet supporting a sink. It also adds a condition to the code section that lets older range and dryer circuits keep using the neutral in place of a separate ground: such a circuit must have GFCI protection. New receptacles must be tamper-resistant under NEC 406.12, which Massachusetts leaves unchanged. > Leave the boxes closed > > Don’t open outlet boxes on old circuits to look for a ground. Old rubber insulation can crack when the wires are moved, and a dead-looking circuit can still be live through a splice elsewhere. Two-prong outlets throughout the house? Start with which circuits they are on. That tells you whether the fix is a device or a rewire. Get an Estimate (617) 405-3599 ## Grounding and bonding at the service Sometimes the problem starts upstream. A house rewired in stages may have a service whose grounding was never brought up to the equipment it now feeds: a ground connection to a water pipe that was later replaced with plastic, a missing bonding jumper around the water meter, or gas piping that was never bonded. Those are checked at the first visit and corrected as part of the job where they fall short. Fixing outlets without fixing the service leaves every circuit with a weaker ground than it appears to have. If the panel itself is the issue, the [fuse box and panel upgrade](https://deckerbostonknobandtube.com/electrical-panel-upgrade/) page covers it. A new panel improves the service end of the ground path, but it adds no ground wire to old branch circuits. ## Insurance, Mass Save and price An outlet-level fix and a circuit replacement can look the same on the wall plate, but they read differently on paper. ### What insurers and Mass Save see Ungrounded outlets often appear on the same home inspection report that mentions knob and tube, and [insurers ask about both](https://deckerbostonknobandtube.com/guide/knob-and-tube-insurance-massachusetts/). A ground-fault outlet on a knob and tube circuit adds protection but leaves the old wiring in service, so it doesn’t settle an insurer’s request or a [Mass Save insulation barrier](https://deckerbostonknobandtube.com/knob-and-tube-insulation-barrier/). Replacing the circuit does, and the written summary should say which outlets are now on grounded circuits. ### What sets the price The price follows what the circuits are made of and how many there are. There is no single figure because outlets on sound later cable can sometimes be handled box by box, while outlets on knob and tube mean fishing new cable. When the job grows into a rewire, a typical Boston-area budgeting range for a whole house is $8,000 to $25,000 or more. The [signs your house needs rewiring](https://deckerbostonknobandtube.com/guide/signs-your-house-needs-rewiring/) guide helps decide which way it is heading, the [danger guide](https://deckerbostonknobandtube.com/guide/is-knob-and-tube-wiring-dangerous/) puts the risk in proportion, and the [cost estimator](https://deckerbostonknobandtube.com/tools/knob-and-tube-cost-estimator/) gives a starting range. ## What's included - Testing each suspect outlet, then opening the box to see what is connected to the ground terminal - Tracing each ungrounded circuit to the panel and recording whether it is knob and tube, cloth-sheathed cable, early armored cable or later ungrounded cable - Finding and undoing bootleg grounds, where the neutral is jumpered to the ground screw - Checking the service grounding and the bonding of water and gas piping at the panel - A written plan for each circuit: replace with grounded cable, add ground-fault protection, or leave a correct two-prong outlet - New grounded, tamper-resistant receptacles on circuits that now have a ground path - Arc-fault and ground-fault protection where Massachusetts requires it on the circuits being changed - The electrical permit filed by the licensed electrician, and a list of which outlets are grounded when the job is done ## Ways to fix an ungrounded outlet | | Replace the circuit with grounded cable | Ground-fault protection on the existing circuit | Leave a two-prong outlet | | --- | --- | --- | --- | | Fits a circuit that is | Knob and tube, brittle cloth cable or overloaded | Sound later two-wire cable that will stay for now | Sound, lightly loaded and feeding nothing that needs a ground | | What you get | A real equipment ground to every outlet on the circuit | Shock protection that trips on leakage; no ground wire | No change in protection | | Surge strips and grounded equipment | Work as designed | Still have no ground path | Can't be plugged in without an adapter, which doesn't ground them | | Openings | Fishing and access holes along the route | Little or none beyond the box | None | | Insurance and Mass Save | Answers the question for that circuit | Leaves the old wiring in service | Leaves the old wiring in service | | Confirm first | Panel space for the new breaker | The plan with the inspector, since Massachusetts deleted the retrofit ground subsection | That the circuit is not knob and tube under insulation | ## Related resources Learn Can you put AFCI and GFCI protection on knob and tube? Ground-fault and arc-fault devices each watch for one kind of failure. On a two-wire circuit they can add real protection, but they don't add a ground and they don't make old wire new. Learn How do you identify knob and tube wiring? A field guide for owners and buyers: where to look in a Boston-area house, what each part of the system looks like, what gets mistaken for it, and where looking stops being enough. Learn Is knob and tube wiring dangerous? Why the same wiring can be sound in one Boston attic and a fire risk in the next, which warning signs need a call this week, and what an inspection can and can't settle. Learn What happens when knob and tube is mixed with Romex? Decades of kitchen remodels and added outlets can leave an old house with new cable spliced onto its original circuits. The cable isn't the weak point. The places where it meets the old wiring are. Decision Guide What are the signs your house needs rewiring? Old houses rarely announce bad wiring with one clear symptom. Sorting what you notice into urgent, worth planning for and not a symptom at all tells you what to do next. ## How a knob and tube job runs from first call to sign-off 1. First call Tell us what prompted the call, the town and type of building, how many units it has, and any deadline from an insurer, a sale or an insulation contractor. Photos, an inspection report or a Mass Save assessment help route the job to the right licensed electrician. 2. Assessment The electrician reviews the panel and the accessible attic and basement wiring, traces circuits, and notes which knob and tube is active, abandoned or mixed. You receive written findings and a scope, with access, patching and permit items listed separately. 3. The work The licensed contractor files the permit, then works area by area so the rest of the house keeps power. New cable is fished or run through open framing, the rough-in is inspected before walls close, and old circuits are disconnected and removed where reachable. 4. Completion Circuits are tested and labeled at the panel, the final inspection closes the permit, and you get the records: what was replaced, what was abandoned in place, and any knob and tube that remains. Those papers answer insurers, buyers and Mass Save. ## What this work looks like New three-prong outlet on an old painted plaster wall above the baseboard Old two-prong outlet pulled from its box in a plaster wall with a multimeter on the baseboard below Find out which outlets are really grounded Testing the boxes and tracing the circuits shows whether the fix is a device, a circuit or a larger rewire. Get an Estimate (617) 405-3599 ## Ungrounded Outlet Upgrades questions ### Can two-prong outlets simply be swapped for three-prong ones? Only where a ground actually reaches the box. A three-prong outlet with nothing on its ground terminal tells anyone plugging in that a ground exists when it doesn't, so a surge strip or an appliance with a metal case has no fault path. On a two-wire circuit the honest choices are a grounded circuit, ground-fault protection planned with the inspector, or keeping a two-prong outlet. Which one fits depends on what the circuit is made of. ### Will a GFCI outlet make a surge protector work on an ungrounded circuit? No. A GFCI cuts power when current leaks out of the circuit, which protects a person touching a faulty appliance, and it does that without a ground wire. A surge protector needs a ground path to send a surge into, and a GFCI doesn't supply one. For computers, audio equipment and anything else that relies on a ground, the circuit needs a real equipment grounding conductor. ### Can a plug-in outlet tester prove an outlet is grounded? It can show that something is wrong, not that everything is right. A plug-in tester reads open ground on most ungrounded outlets, but a bootleg ground, a jumper from the neutral to the ground screw, makes it read correct while there is still no ground. It also can't tell knob and tube from later cable or test how good a ground path is. An electrician confirms it at the box and back at the panel. ### Can a ground wire be added to knob and tube without rewiring the circuit? Not in any way worth relying on. Knob and tube was built as two separate conductors with no grounding means anywhere along the run, and Massachusetts has deleted the NEC subsection that sets out options for retrofitting a ground connection to an existing outlet. In practice, giving a knob and tube outlet a real ground means replacing the circuit with grounded cable. Any plan short of that is confirmed with the inspector first. ### What sets the price of fixing ungrounded outlets? Mostly what the circuits are made of. Outlets on later two-wire cable can sometimes be dealt with box by box, while outlets on knob and tube usually mean replacing the circuit, which brings in fishing, openings and patching. Beyond that, the price follows the number of outlets and circuits, attic and basement access, plaster, panel space for new breakers and the permit, which in Boston is a $20 application fee plus $1 per fixture, plug or outlet and $5 per meter. ## Related services ### Partial Replacement → The circuits still on knob and tube replaced from the panel to the last device, with a written record of anything left for a later phase. ### Cloth Wiring Replacement → Rubber-and-cloth insulated cable from the decades after knob and tube, assessed run by run and replaced with grounded, arc-fault protected circuits. ### Fuse Box and Panel Upgrades → Fuse boxes and full panels replaced, and 60 or 100 amp services enlarged where the load calculation calls for it, planned together with the rewire.