Product images: Amazon listings
Written from the listing's specs, not from our own use · How we rate
We like the 6699 Flushing Kit (1/4 HP Pump) for the mix: a 1/4 HP pump and a 3-gallon pail. Think of it for a hard-water house that flushes every year: 6.9/10 on what its listing documents.
| Brand | 6699 |
|---|---|
| Category | Service kits, valves & parts |
| Pump | 1/4 HP, 1,500 GPH |
| ASIN | B0BTS2VT5M |
Full listing title: 6699 Tankless Water Heater Flushing Kit, 1/4 HP Pump, 2 Hoses, 3 Gal Pail
Rated from the listing's specs, no buyer reviews yet
What it's made for: a hard-water house that flushes every year.
Two flush kits close to it on our rating, each with a dated price.
The pump the listing states, rated 1,500 GPH. It pushes the solution through the heat exchanger and back into the pail for about an hour; the hoses have to reach from the service valves down to the bucket.
What it has going for it
3-gallon pail. The bucket the solution circulates through. A lid keeps the splashes off the garage floor.
Yourself: the kit gives you a 1/4 HP pump and a 3-gallon pail, per the listing. With service valves on the heater, it's an hour with a bucket on the garage floor.
Book the plumber: if your heater has no service valves yet, the first visit is to put them in. After that, this kit does the yearly job.
The seller states, word for word, in the 6699 Flushing Kit (1/4 HP Pump) listing:
1/4HP energy-efficient motor with thermal overload protection, has the ability to deliver water to maximum height 23 feet and flow rate is 1500GPH, quietly running.
Pump Volts/Hertz: 115V/60Hz.
Quoted from the listing, not checked by us. Hold every figure against your own heater before you order.
What the 6699 Flushing Kit (1/4 HP Pump) listing names:
Check these figures against your heater's manual before you order.
On Sep 30, 2026, that price put it in the cheaper third of the 10 flush kits we have a recent price for.
The descaler isn't in the box, so add a bottle (or a few gallons of vinegar, if your manual allows it).
The button opens the exact listing (ASIN B0BTS2VT5M), where today's price, stock and seller apply.
Want the descaler in the box? The Chromex Flush Kit, Concentrated Vinegar (7.4/10) comes with it, per its listing.
Our take
The 6699 Flushing Kit (1/4 HP Pump) earns its place with a 1/4 HP pump and a 3-gallon pail. No buyer reviews yet, so the 6699 Flushing Kit (1/4 HP Pump) has to win you over on paper. The catch with this 6699 flush kit: without service valves on your heater, there is nothing to hook it up to. We'd pick it if you would rather flush it yourself than book a service call; otherwise, put it next to the 6699 Flushing Kit (1/6 HP Pump) first.
Before you order the 6699 Flushing Kit (1/4 HP Pump), check your service valves: its 1/4 HP pump needs isolation valves with service ports on your heater to connect to.
Most makers name the descaler or the vinegar they accept, and some warranties depend on it. Check before you pour.
Look under the heater for two valves with small side ports on the hot and cold lines. That is where the flush hoses attach.
A 1/4 HP pump, a bucket and about an hour. Our flushing and descaling guide walks through the steps.
How the 6699 Flushing Kit (1/4 HP Pump) stacks up against the closest alternative, the 6699 Flushing Kit (1/6 HP Pump).
| Criterion | 6699 Flushing Kit, 1/4 HP Pump | 6699 Flushing Kit, 1/6 HP Pump |
|---|---|---|
| Our rating | 6.9/10 | 7.0/10 |
| Pump | 1/4 HP | 1/6 HP |
| Pail | 3 gal | 3 gal |
Pick the 6699 Flushing Kit (1/6 HP Pump) if you want our higher-rated option (7.0/10).
We rate it 6.9/10 (good). The rating comes from its documented listing alone, as no customer-review record is captured yet.
Its listing states a 1/4 HP pump and a 3-gallon pail. These are the seller's figures, not our measurements: whether it fits your exact heater is worth confirming first.
Your heater's manual: most makers name the descaler or the vinegar they accept, and some warranties depend on it. Check before you pour. Service valves: look under the heater for two valves with small side ports on the hot and cold lines. That is where the flush hoses attach. The setup: a 1/4 HP pump, a bucket and about an hour. Our flushing and descaling guide walks through the steps.
We link to the exact listing on Amazon, where today's price, stock and seller apply. It is an affiliate link, and it has no effect on the rating.
No, we haven't used it ourselves. Everything on this page comes from its listing, read line by line and weighed with our published formula.