Is it safe to use drain cleaner in garbage disposals? Generally, the answer is no. Unfortunately I speak from experience.
Why drain cleaner in garbage disposals is a bad idea
In my experience, if your garbage disposal works well and doesn’t leak, putting drain cleaner in the garbage disposal is just about the fastest way to make it leak. I made the mistake once myself in my own house, and frequently when a tenant calls me and says the garbage disposal is leaking, there’s a bottle of drain cleaner sitting next to the kitchen sink when I arrive.
Manufacturers warn that putting drain cleaner in garbage disposals will quickly cause the internal parts to corrode. Furthermore, it voids the warranty, and it’s easy to tell when a disposal has had drain cleaner put in it. That’s a paraphrase of what you’ll find in the manual that comes with most disposals, but the warning is there.
There are cleaners that claim to be safe to use in disposals. If you’re going to use a drain cleaner in a disposal, at least make sure it’s one that’s designed to be used with a disposal. Ideally the cleaner should come with a guarantee. That is, a guarantee not to damage the disposal, not just a guarantee to clear the pipes. There is a difference.
These designed-for-disposal products often don’t do much for clogs, however. The corrosive stuff that’s bad for disposals is also the stuff that clears the pipes. So clear the drain with a plunger rather than using a chemical. If the plunger fails, snake out the drain instead.
These fixes take longer than using drain cleaner but they won’t ruin a disposal. And if you have to pay someone to snake out a drain, it won’t cost any more than the labor to install a disposal. Keep in mind the disposal itself costs about $75.
An ounce of prevention
To avoid clogging up a kitchen sink in the first place, be careful what you put down the drain. Throw bones and corn cobs in the trash rather than putting them down the disposal. Pour grease into a jar or a tin can and throw it in the trash, rather than putting it down the disposal. Egg shells and coffee grounds are OK if you’re sure there’s no grease in your pipes. If there is, they can get stuck in the grease and cause a clog. If in doubt, throw your egg shells and coffee grounds in the trash instead.