DIY Dishwasher Installation?
April 19, 2024 6:46 PM Subscribe
We currently have a pull-out portable dishwasher and we'd like to get and hook up a permanent dishwasher. Is this doable for somebody that doesn't know any plumbing beyond righty-tighty/lefty-loosey? Anything I'm not thinking of?
Our building does not allow dishwashers to drain directly to the plumbing, but it does allow dishwashers that drain to the sink. We currently have a portable dishwasher that hooks up to our sink faucet and returns the water there. We'd like to permanently install a normal, non-portable dishwasher that also drains to the sink.
As I understand it, I would need to: 1) split off the hot water from under our sink and connect that to the dishwasher intake, 2) connect the dishwasher exit line to a hose that drains into a sink, and 3) plug the dishwasher into an electrical outlet.
Is it actually that simple? Are there a bunch of rookie mistakes I'm likely to make doing this? Lots of tools I don't realize I need? Problems with water flowing uphill or something? Or should we just call a professional because water equals expensive risk to home?
Our building does not allow dishwashers to drain directly to the plumbing, but it does allow dishwashers that drain to the sink. We currently have a portable dishwasher that hooks up to our sink faucet and returns the water there. We'd like to permanently install a normal, non-portable dishwasher that also drains to the sink.
As I understand it, I would need to: 1) split off the hot water from under our sink and connect that to the dishwasher intake, 2) connect the dishwasher exit line to a hose that drains into a sink, and 3) plug the dishwasher into an electrical outlet.
Is it actually that simple? Are there a bunch of rookie mistakes I'm likely to make doing this? Lots of tools I don't realize I need? Problems with water flowing uphill or something? Or should we just call a professional because water equals expensive risk to home?
Best answer: It is that simple, pretty much.
Standard practice in Australia is to hook dishwashers up to cold water only, letting the machine heat its own water as needed. Starting wash cycles on cold is good for shifting dried-up stuff off the dishes instead of cooking it on, and the relative inefficiency of the resistive water heater inside the dishwasher isn't really consequential because the volume of water being heated per cycle is so small compared to a bath or shower or even a soapy sinkful.
Most dishwashers also have a timed start feature, which can work well if your local electricity retailer offers time-of-use tariffs.
Australian dishwashers are also routinely supplied via a plug and a standard electrical outlet, which simplifies installation. If you live somewhere whose standard outlets provide only anaemic half-strength American electricity, then depending on your dishwasher model you might need to get a sparky in to organize 240V power for it.
Our building does not allow dishwashers to drain directly to the plumbing
What your building "allows" and what it's actually fitted with might be two different things. Under-sink drainage fittings with a little barbed spur off the side that's specifically designed to take a dishwasher drainage hose are super common. As supplied, these are blanked off. If your sink has one, all you need to do in order to use it is run a half-inch drill down inside it to open up the dead end, then fit the drain hose over the barb and secure it with a hose clamp.
When you eventually remove the dishwasher you can just wipe the spur out thoroughly with a rag on the end of a stick and squirt a goodly blob of silicone caulk inside to seal it back up, and nobody will be the wiser.
You'd also want to use a hose clip to secure the drain hose to the underside of the sink bench so that a loop of it sits as high as possible between dishwasher and sink drain. This limits the tendency for your drainage drain hose to siphon water back into the machine whenever you pull the plug in the sink. If you're complying strictly with your building management's policy and running the drain hose high enough to empty into the sink, that won't be an issue. The dishwasher's drainage pump should have no trouble overcoming the extra few inches of head.
posted by flabdablet at 9:05 PM on April 19, 2024 [1 favorite]
Standard practice in Australia is to hook dishwashers up to cold water only, letting the machine heat its own water as needed. Starting wash cycles on cold is good for shifting dried-up stuff off the dishes instead of cooking it on, and the relative inefficiency of the resistive water heater inside the dishwasher isn't really consequential because the volume of water being heated per cycle is so small compared to a bath or shower or even a soapy sinkful.
Most dishwashers also have a timed start feature, which can work well if your local electricity retailer offers time-of-use tariffs.
Australian dishwashers are also routinely supplied via a plug and a standard electrical outlet, which simplifies installation. If you live somewhere whose standard outlets provide only anaemic half-strength American electricity, then depending on your dishwasher model you might need to get a sparky in to organize 240V power for it.
Our building does not allow dishwashers to drain directly to the plumbing
What your building "allows" and what it's actually fitted with might be two different things. Under-sink drainage fittings with a little barbed spur off the side that's specifically designed to take a dishwasher drainage hose are super common. As supplied, these are blanked off. If your sink has one, all you need to do in order to use it is run a half-inch drill down inside it to open up the dead end, then fit the drain hose over the barb and secure it with a hose clamp.
When you eventually remove the dishwasher you can just wipe the spur out thoroughly with a rag on the end of a stick and squirt a goodly blob of silicone caulk inside to seal it back up, and nobody will be the wiser.
You'd also want to use a hose clip to secure the drain hose to the underside of the sink bench so that a loop of it sits as high as possible between dishwasher and sink drain. This limits the tendency for your drainage drain hose to siphon water back into the machine whenever you pull the plug in the sink. If you're complying strictly with your building management's policy and running the drain hose high enough to empty into the sink, that won't be an issue. The dishwasher's drainage pump should have no trouble overcoming the extra few inches of head.
posted by flabdablet at 9:05 PM on April 19, 2024 [1 favorite]
If you also install a garbage disposal, they nicely accommodate your dishwasher drain hose.
posted by hortense at 10:20 PM on April 19, 2024
posted by hortense at 10:20 PM on April 19, 2024
Best answer: Installing a dishwasher is relatively simple if the connections already exist.
But creating the proper connections (water, electrical, drain) for a built-in unit is .... not for someone whose experience is limited to righty-tighty. There are a lot of "it depends" situations for each of those domains.
In the US it's common for dishwashers to connect to the sink via an air gap and a disposal. I think connecting straight to drain is probably uncommon.
posted by Dashy at 4:02 AM on April 20, 2024 [3 favorites]
But creating the proper connections (water, electrical, drain) for a built-in unit is .... not for someone whose experience is limited to righty-tighty. There are a lot of "it depends" situations for each of those domains.
In the US it's common for dishwashers to connect to the sink via an air gap and a disposal. I think connecting straight to drain is probably uncommon.
posted by Dashy at 4:02 AM on April 20, 2024 [3 favorites]
Best answer: - Are your pipes galvanized, copper, PVC, or PEX? (Or something else?)
- Will the new unit use a plug or need to be hardwired?
- If it uses a plug, do you know what else is on that circuit?
- Is that circuit rated to handle the total electrical load?
- If it needs to be hardwired, are you confident about matching it to a circuit rated to handle the load?
- Do you have access to your electrical panel and know which breaker to flip to cut power to the circuit?
...If those questions sound like a foreign language to you, get someone else to do it.
...If the questions sound like your native language, but you have no Idea how to find the answers, get someone else to do it.
...If you understand the questions and know all the answers of the top of your head, see if you can find an in installation manual online for your specific new unit, or a YouTube how-to for your specific unit. Read and/or watch them. If you're reasonably confident you can do the work, go ahead and attempt it.
¡ Remember to cut power to the circuit before you do !
posted by cocoagirl at 4:41 AM on April 20, 2024 [2 favorites]
- Will the new unit use a plug or need to be hardwired?
- If it uses a plug, do you know what else is on that circuit?
- Is that circuit rated to handle the total electrical load?
- If it needs to be hardwired, are you confident about matching it to a circuit rated to handle the load?
- Do you have access to your electrical panel and know which breaker to flip to cut power to the circuit?
...If those questions sound like a foreign language to you, get someone else to do it.
...If the questions sound like your native language, but you have no Idea how to find the answers, get someone else to do it.
...If you understand the questions and know all the answers of the top of your head, see if you can find an in installation manual online for your specific new unit, or a YouTube how-to for your specific unit. Read and/or watch them. If you're reasonably confident you can do the work, go ahead and attempt it.
¡ Remember to cut power to the circuit before you do !
posted by cocoagirl at 4:41 AM on April 20, 2024 [2 favorites]
Best answer: Australian dishwashers are also routinely supplied via a plug and a standard electrical outlet, which simplifies installation. If you live somewhere whose standard outlets provide only anaemic half-strength American electricity, then depending on your dishwasher model you might need to get a sparky in to organize 240V power for it.
If you live in a place with 120V electricity, the dishwasher will almost certainly be made to use that. In the US, kitchens will typically have a 240V outlet for the stove, but all other appliances will be on 120. However, this depends on where you live; I've been in a lot of places where there are more hybrid approaches with people mixing and matching appliances from both 120V and 240V countries.
Regardless, yes, the theory is pretty simple (connect to power using an appropriate outlet that can supply the necessary power safely, connect to the water supply, connect to a drain) but depending on how water, power, and drains are set up in your kitchen this could be more complicated. The typical sink drain connection is via a fitting under the sink (usually after passing through an air gap). Your choice will probably be to illicitly connect to an under-sink fitting (which it sounds like your building does not allow), or to run a hose up through or behind the counter and then drain into the sink, sort of like how a washing machine drain hose might be connected sometimes.
If you do drain directly into the sink, you'll obviously want to ensure that there is never, ever a sink plug in place while the dishwasher is running.
posted by Dip Flash at 6:47 AM on April 20, 2024
If you live in a place with 120V electricity, the dishwasher will almost certainly be made to use that. In the US, kitchens will typically have a 240V outlet for the stove, but all other appliances will be on 120. However, this depends on where you live; I've been in a lot of places where there are more hybrid approaches with people mixing and matching appliances from both 120V and 240V countries.
Regardless, yes, the theory is pretty simple (connect to power using an appropriate outlet that can supply the necessary power safely, connect to the water supply, connect to a drain) but depending on how water, power, and drains are set up in your kitchen this could be more complicated. The typical sink drain connection is via a fitting under the sink (usually after passing through an air gap). Your choice will probably be to illicitly connect to an under-sink fitting (which it sounds like your building does not allow), or to run a hose up through or behind the counter and then drain into the sink, sort of like how a washing machine drain hose might be connected sometimes.
If you do drain directly into the sink, you'll obviously want to ensure that there is never, ever a sink plug in place while the dishwasher is running.
posted by Dip Flash at 6:47 AM on April 20, 2024
Best answer: What your building "allows" and what it's actually fitted with might be two different things.
I would very much counsel against doing something that goes against the co-op/condo rules or the terms of your lease, whichever applies. Many times these things are disallowed specifically because of old plumbing, narrow or narrowed pipes, etc. When dishwashers pump water directly into a drain line that can’t accommodate the flow rate, this can result in waste water coming up through your sink’s drain or, even worse, coming up through your neighbor’s sink’s drain, or even more worse, eventually creating leaks. If anything like that happens, it’ll be your ass in a sling since you knowingly broke the rules. When the waste water drains into a basin with a drain, on the other hand, it runs out through the drain line at whatever flow rate the drain line can accommodate.
You should (I think) be able to install a non-portable dishwasher connected to the water supply but with the drain line going into the kitchen sink. You’ll want to get an actual plumber involved for that, because there will be considerations as to the configuration and angle of the waste water line coming out of the dishwasher, need for a trap, etc. The complicated bit will be due to the fact that the waste water drains out of the bottom of the dishwasher and then has to travel upwards to reach sink height. You’ll probably also want a pro to make sure the fit and finish looks nice. This is something I would hesitate to DIY.
Do others in the building have a setup similar to what you envision? Checking with them would be a good starting point.
posted by slkinsey at 6:12 AM on April 21, 2024
I would very much counsel against doing something that goes against the co-op/condo rules or the terms of your lease, whichever applies. Many times these things are disallowed specifically because of old plumbing, narrow or narrowed pipes, etc. When dishwashers pump water directly into a drain line that can’t accommodate the flow rate, this can result in waste water coming up through your sink’s drain or, even worse, coming up through your neighbor’s sink’s drain, or even more worse, eventually creating leaks. If anything like that happens, it’ll be your ass in a sling since you knowingly broke the rules. When the waste water drains into a basin with a drain, on the other hand, it runs out through the drain line at whatever flow rate the drain line can accommodate.
You should (I think) be able to install a non-portable dishwasher connected to the water supply but with the drain line going into the kitchen sink. You’ll want to get an actual plumber involved for that, because there will be considerations as to the configuration and angle of the waste water line coming out of the dishwasher, need for a trap, etc. The complicated bit will be due to the fact that the waste water drains out of the bottom of the dishwasher and then has to travel upwards to reach sink height. You’ll probably also want a pro to make sure the fit and finish looks nice. This is something I would hesitate to DIY.
Do others in the building have a setup similar to what you envision? Checking with them would be a good starting point.
posted by slkinsey at 6:12 AM on April 21, 2024
Best answer: If you do drain directly into the sink, you'll obviously want to ensure that there is never, ever a sink plug in place while the dishwasher is running.
Not obvious to me. A typical dishwasher uses under 15 litres of water to run a load, and a typical sink will hold at least 30. Worst case, then, is that running the dishwasher could potentially half fill the sink with hot and somewhat caustic dishwater. Could be just the thing for soaking the stubborn burnt bits off that baking dish.
The complicated bit will be due to the fact that the waste water drains out of the bottom of the dishwasher and then has to travel upwards to reach sink height.
Not an issue. Dishwashers have drainage pumps. They have these because they're almost always installed with the end of their drain hose well above the level of their internal sump.
When dishwashers pump water directly into a drain line that can’t accommodate the flow rate, this can result in waste water coming up through your sink’s drain or, even worse, coming up through your neighbor’s sink’s drain, or even more worse, eventually creating leaks.
The flow rate out of a dishwasher drainage pump is nowhere near as high as that from a sink full of dishwater whose plug has just been pulled, as long as the drain isn't blocked somewhere below the sink's own P trap.
If it is blocked to the extent that the sink drains only very slowly, the only result of the dishwasher being pumped into the drain above that P trap - which is where the dishwasher drainage spur I mentioned above is - will be that some of the water being pumped out of the dishwasher rises up through the plughole and spends a bit of time in the sink.
This creates no more pressure inside the drains than deliberately draining the dishwasher into the sink would do. Your neighbours are no more likely to get a visit from your dishwasher's effluent than they are to have seen anything else that's ever drained out of your sink, and if they do ever see that, it's because the building's drains are in such poor condition as to require immediate remediation.
In particular, jumping through extra installation hoops to force your dishwasher to drain through your sink's plughole, rather than entering the exact same pipe six inches below that plughole, will change nothing about what happens downstream of the sink's P trap.
If your building's rules genuinely prohibit connecting dishwashers to the drainage points specifically designed for dishwashers, then your building's rules are stupid. The only rationale I can think of for such a rule is to prevent a scenario where a tenant, having once installed a dishwasher, then moves out and takes the dishwasher with them without closing that drain spur back up again - because if it's just sitting there open, with nothing connected to it, and the sink drain does get clogged downstream of its P trap, then the dishwasher spur will spurt greywater into the under-sink cupboard every time the plug is pulled and nobody wants that. Seal it back up when you're done with it and it won't cause any problems.
posted by flabdablet at 7:02 AM on April 21, 2024 [1 favorite]
Not obvious to me. A typical dishwasher uses under 15 litres of water to run a load, and a typical sink will hold at least 30. Worst case, then, is that running the dishwasher could potentially half fill the sink with hot and somewhat caustic dishwater. Could be just the thing for soaking the stubborn burnt bits off that baking dish.
The complicated bit will be due to the fact that the waste water drains out of the bottom of the dishwasher and then has to travel upwards to reach sink height.
Not an issue. Dishwashers have drainage pumps. They have these because they're almost always installed with the end of their drain hose well above the level of their internal sump.
When dishwashers pump water directly into a drain line that can’t accommodate the flow rate, this can result in waste water coming up through your sink’s drain or, even worse, coming up through your neighbor’s sink’s drain, or even more worse, eventually creating leaks.
The flow rate out of a dishwasher drainage pump is nowhere near as high as that from a sink full of dishwater whose plug has just been pulled, as long as the drain isn't blocked somewhere below the sink's own P trap.
If it is blocked to the extent that the sink drains only very slowly, the only result of the dishwasher being pumped into the drain above that P trap - which is where the dishwasher drainage spur I mentioned above is - will be that some of the water being pumped out of the dishwasher rises up through the plughole and spends a bit of time in the sink.
This creates no more pressure inside the drains than deliberately draining the dishwasher into the sink would do. Your neighbours are no more likely to get a visit from your dishwasher's effluent than they are to have seen anything else that's ever drained out of your sink, and if they do ever see that, it's because the building's drains are in such poor condition as to require immediate remediation.
In particular, jumping through extra installation hoops to force your dishwasher to drain through your sink's plughole, rather than entering the exact same pipe six inches below that plughole, will change nothing about what happens downstream of the sink's P trap.
If your building's rules genuinely prohibit connecting dishwashers to the drainage points specifically designed for dishwashers, then your building's rules are stupid. The only rationale I can think of for such a rule is to prevent a scenario where a tenant, having once installed a dishwasher, then moves out and takes the dishwasher with them without closing that drain spur back up again - because if it's just sitting there open, with nothing connected to it, and the sink drain does get clogged downstream of its P trap, then the dishwasher spur will spurt greywater into the under-sink cupboard every time the plug is pulled and nobody wants that. Seal it back up when you're done with it and it won't cause any problems.
posted by flabdablet at 7:02 AM on April 21, 2024 [1 favorite]
Best answer: In terms of electrical supply, if you are plugging in a washer, it must be plugged to a GFI on a breaker with capacity. If your kitchen is up to code, I expect all outlets to be GFIs.
Also, most dishwashers specify a need for a dedicated 10A or 20A (110v) breaker and prohibit the use of an extension cord. If you’re in an apartment, this might be doable by identifying an outlet close to the dishwasher (less than 6 feet). Then, identify all outlets that share the same breaker as that outlet, and ensure they aren’t used (putting outlet covers up, etc.)
posted by Headfullofair at 12:48 PM on April 21, 2024
Also, most dishwashers specify a need for a dedicated 10A or 20A (110v) breaker and prohibit the use of an extension cord. If you’re in an apartment, this might be doable by identifying an outlet close to the dishwasher (less than 6 feet). Then, identify all outlets that share the same breaker as that outlet, and ensure they aren’t used (putting outlet covers up, etc.)
posted by Headfullofair at 12:48 PM on April 21, 2024
« Older Could my daughter's closeted girlfriend's parents... | Duplicate for Starbucks Via instant coffee Newer »
You are not logged in, either login or create an account to post comments
posted by being_quiet at 8:38 PM on April 19, 2024 [2 favorites]