If your tub fills very slowly, the faucet is rarely the reason. Ella fast fill faucets are designed for unrestricted flow, up to 16 gallons per minute on the 2-piece set and 18 gallons per minute on the 5-piece set at 60 PSI with ideal plumbing, so a slow fill points at the house side: water pressure, supply line size, a shutoff that is not fully open, or a thermostatic valve whose intake screens have clogged with scale. The first thing to check is both shutoff valves behind the access panel, because a valve that is only partly open is the most common and easiest fix.

Likely Causes

• Low household water pressure. The rated flow assumes 60 PSI, and lower pressure means a slower fill.
• Supply shutoffs that are not fully open, a kinked supply line, or long runs of 1/2 inch house pipe feeding a faucet piped for 3/4 inch.
• Scale on the TCV intake screens or check valve, which chokes flow to a trickle even when the water is hot.
• A thermostatic or pressure valve an installer added to the hot line, which can reduce flow.
• A tankless water heater with a low flow rating.

What to Check, in Order

1. Confirm both shutoff valves are fully open. The supply lines and shutoff valves guide explains where they are and why they should be reachable through the access panel.
2. Compare with another fixture. If pressure is low everywhere in the house, the fix is on the house side; if it is low only at the tub, look at the tub's own supply run and valves.
3. Note your supply line size. Your existing 1/2 inch lines will work; 3/4 inch lines fill faster but are not required. The faucet itself ships with two 3/4 inch by 5 foot braided supply lines.
4. On a thermostatic faucet, have your plumber inspect the TCV intake screens and the check valve at the bottom of the cartridge, and clean them with a soft brush and a lime scale remover. Protecting the TCV in hard water covers the inline filter that keeps them clear.
5. Check your water heater. A 75 gallon or larger tank is recommended, and a tankless heater should be rated 11 gallons per minute or higher; what size water heater you need walks through it.
6. Set realistic expectations. In real homes a fill runs about 7 to 15 minutes depending on the size of the tub and your plumbing; fast fill faucet expectations shows the capacity of each model.

When to Open a Ticket

If the shutoffs are open, pressure is fine elsewhere in the house, and the tub still takes far longer than 15 minutes, open a ticket with your serial number, a photo of the faucet set, a photo of the supply lines and shutoffs behind the access panel, your supply line size, and whether any valve or filter was added to the hot line. The team confirms the cause from those details; reach them through your Ella dealer or at ellasbubbles.com/support or (800) 480-6850.

Common Questions