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Fast Plumbing Answers: No Hot Water from Shower Valve
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You rolled out of bed for a nice, hot shower this morning- and got a blast of cold water instead. You checked the water heater, and it’s working fine- and so is every other hot water faucet in the house. One thing’s for sure- you don’t want any more icy cold showers.
When you called your plumber (or your DIY buddy), they talked about your shower cartridge. They’re probably right- but you’ve never heard of one of those. So what is a shower cartridge, why is it broken, and how do you fix it?
Don’t worry: we’ll answer all your questions in 2 minutes or less.
At Mother, we solve the real-world problems that homeowners face every day. Our plumbers see first-hand the damage that hard water, mineral deposits and stuck cartridges cause to your shower valve- and we’re here to help.
Live in Dallas? Call us 24/7 if your shower valve or cartridge is acting up. Our fully stocked vans mean we’ll fix the problem in one appointment on the same day you call.
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The Problem: Cold Showers, But Your Water Heater’s Fine
We get why this is frustrating- you take great care of your hot water heater, and make sure it always gets flushed on time. You expect the peace and relaxation that comes with a hot shower in return.
But issues with the shower cartridge can lead to blocked hot water delivery, even if your water heater’s relatively healthy. Our Master Plumber Jesse Crane says poor water quality is to blame for most of these issues.
“The internal parts are usually rubber and plastic,” Jesse explains. “All the chlorine and minerals in our water just wreak havoc on them.”
The Reason Why: A Damaged Shower Cartridge
Think of your shower cartridge as the traffic cop in the middle of an intersection. It’s a small cylinder inside your shower handle that has two important jobs:
- Directs the flow of hot and cold water. When you turn the handle, the cartridge moves to open your hot and cold water inlets.
- Mixes hot and cold water to your liking. Based on how far you turn the handle, it lets the right amounts of hot and cold water through to create the temperature you want.
A healthy cartridge does all the hard work that leads to a perfect shower. When your cartridge is clogged, damaged or broken, the flow of water into your shower head is blocked. This is why your hot water’s not coming through.
Jesse tells customers most shower cartridge leaks happen due to one of these issues:
- Worn out seals (the most common reason)
- Clogs and mineral buildup
- Broken, “stuck” cartridges
Worn out seals
“Age is the primary reason for internal damage,” Jesse says. “Usually it’s worn out seals= rubber parts degrade over time.”
Shower cartridges have small seals and O-rings inside that separate the cold and hot water channels and keep your water flowing in the right direction.
These seals and O-rings are made from rubber or plastic. The longer they’re in place and exposed to hot water and hard minerals, the more they break down.
When the seal fully breaks down, there’s nothing to prevent cold water from flowing back into the hot water inlet. This means the hot water from your water heater doesn’t make it up to your shower head- all you get is an icy cold shower.
If your water isn’t especially hard, check the incoming water pressure. “High pressure on the incoming water causes parts to break down prematurely,” Jesse advises.
Clogs and mineral buildup
Hard water contains minerals like calcium and magnesium. As these minerals travel towards your shower, they create deposits along the way- like the gunky white calcium buildup on your faucets.
Hot water lines are more likely to accumulate minerals than cold lines. That’s because the minerals in hard water are less soluble when the water is hot- they start to “fall out” and stick to your pipes and fixtures as the water flows through.
“Mineral scaling definitely happens inside the brass body of the valve,” Jesse tells us.
Since the area inside your shower cartridge is so small, it’s a magnet for mineral scaling and accumulation. The same white, chalky scaling you see on your faucets ends up trapped in the cartridge- blocking hot water from entering.
Mineral buildup clogging your shower fixtures? Learn how to stop calcium buildup on faucets and shower heads!
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Broken, “stuck” cartridges
This occurs when there’s actual physical damage to your cartridge. These breaks usually happen inside the cartridge- when they do, your cartridge gets “stuck” in the cold water position, not allowing any hot water through.
Breaks are more common in plastic shower cartridges- they’re made from a more brittle material and easier to crack.
Jesse also told us that several customers had broken cartridges due to internal damage in their water heater.
“A couple times I’ve taken out a cartridge out, and pieces of the dip tube from an old water heater had gotten into the water system,” he explains. “They end up clogging the cartridge.”
The Answer: Quick, Easy Shower Cartridge Replacement
We like when the solution to your plumbing problem is this straightforward! All you need to do to fix any of these problems is call your plumber for a new shower cartridge.
Reliable plumbers have the parts and staffing to get your cartridge replaced quickly. Mother’s fully-stocked vans mean you get a new cartridge in one appointment, in a tight time window, on the same day you call.
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DIY cartridge replacement is for extremely handy folks
Expert DIYers with some plumbing experience can replace their own shower cartridge- but if you’re unfamiliar with the process, our plumbers strongly suggest calling a pro.
There are a few inherent risks to DIY cartridge replacement- primarily with causing damage to larger components and buying inferior parts:
- Valve damage. Your cartridge is housed inside a larger, more intricate valve. Yank or force a stuck cartridge out, and you risk bending or cracking the valve itself. If you do, it turns into a shower valve repair that involves removing shower tile and opening up your bathroom wall- a job that easily totals $1,000+.
- Incorrect insertion. Inexperienced homeowners can easily insert the new cartridge 180° in the wrong direction. This reverses your hot and cold flows.
- Insufficient seals. If your seals and O-rings aren’t properly lubricated and set, they’ll immediately cause in-wall leaks the first time you turn on the shower.
- Buying a shoddy replacement. You can grab a replacement cartridge from Lowe’s or Home Depot for $35-$50- but you’re getting a cheap plastic part that isn’t any better than the existing broken one. If your shower is old (pre-1990), you’ll need a conversion kit as well.
If you’re determined to DIY the job, purchase a quality shower cartridge with brass components, from brands like Delta or Moen. You’ll pay more, but you’ll have a longer-lasting replacement.
A second solution: inline water softener for the shower
If you’re tired of constant mineral buildup and hard water problems in your shower (this happens near us in Dallas a lot), install an inline water softener on your shower.
It’s far less expensive than a whole home water softener, and keeps calcium and magnesium from reaching your shower water inlets in the first place.
You’ll keep your shower cartridge free of clogs- plus, you’ll get rid of dry skin, tangled hair and brittle nails after you shower.
Replace Your Shower Cartridge With One Easy Call
When sediment, damaged seals or broken parts block your shower cartridge, it keeps hot water out of your shower- even if your hot water heater’s working just fine.
Most reputable, licensed plumbers can fix this problem quickly and easily- a new cartridge with quality materials (like brass) restores proper water flow and gives you the hot, powerful showers you deserve.
If you live in Dallas-Fort Worth, call Mother 24/7- we’ll send a licensed pro with a new shower cartridge at the first-available same day appointment!
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