Electric Shower: Monthly Cost of the Summer/Winter Settings (and When to Replace the Heating Element)
Your electric shower’s “winter” setting costs more because it runs at higher power (watts). Learn how to calculate the monthly cost for each setting using your shower’s wattage, your shower time, and your bill’s R$/kWh—+
- What the ‘Summer/Winter’ Settings Actually Change
- What You Need to Calculate your End-of-Month Cost
- How to find your R$/kWh (without guesswork)
- The Calculator (works for summer and winter)
- Worked Example. Summer versus Winter End of Month Cost
- When to replace the heating element (and how to avoid burning it early)
- Common Mistakes That Ruin Your Cost (or Create Failures)
- FAQ
- Referências
TL;DR
To get that monthly cost for each setting you need: 1) the power drawn by the shower (in kW) for that setting, 2) the approximate number of minutes you use it for, and 3) your effective price on the kWh.
So the formula for energy is simply: Energy (kWh) = Power (kw) * Time (hours). To get the monthly cost, you multiply the “Monthly kWh” by your cost of kWh at the bottom.
Winter costs more solely because it uses more power (watts). If used for the same length of time, say the “Winter” position on your shower uses 5.5 kW and “Summer” uses 3.3 kW, then it is using some 40% less energy.
Replace the heating element when the hot water no longer heats up (or only heats intermittently), when the breaker/RCD constantly trips, or just some obvious signs of damage; just ensure you always used the exact correct replacement part for the make/model of your individual shower, as well as the same exact replacement for the voltage.
What the ‘Summer/Winter’ Settings Actually Change
What You Need to Calculate your End-of-Month Cost
- Power for each setting (kW): ideally from your manual (winter/hot vs summer/warm). If you only have maximum power: worst cost(max).
- Daily usage: minutes per shower x number showers day.
- Billing cycle days: use number of days on your bill (it maybe not exactly 30).
- Your effective price (R$/kWh): use the total unit price in your bill, or estimate it from the totalling (explained below).
How to find your R$/kWh (without guesswork)
- If you can find itemized charges on your bill, you may find for example the energy price as a unit price per kWh for items like TE and/or TUSD (and then taxes/flags).
- Also for a quick practical estimate, we can work out the total bill amount (R$) divided by total consumption (kWh). This is obviously all figures including taxes/flags, but is usually sufficient comparison with the “summer vs winter”.
- In order to properly understand what is included in the price, in the available tariff information ANEEL outlines some tariffs tools and reports, and the distributors often explain how the TE and TUSD appears on the invoice.
The Calculator (works for summer and winter)
Use these two formulas (they’re the same for any appliance):
Monthly energy(kWh) = Power (kW) x (x minutes per day ÷ 60) x (billing days)
Monthly cost(R$) = Monthly energy(KWh) x Effective price (R$/kWh)
Quick “cost per minute” shortcut
If your effective price is 1.00 R$/kWh, then the cost per minute is simply: kW ÷ 60. Multiply by your R$/kWh if necessary.
| Power setting(kW) | kWh per 10 minutes | Example cost per 10 minutes at 1.00 R$/kWh |
|---|---|---|
| 3.2 kW | 0.53 kWh | R$ 0.53 |
| 4.5 kW | 0.75 kWh | R$ 0.75 |
| 5.5 kW | 0.92 kWh | R$ 0.92 |
| 6.8 kW | 1.13 kWh | R$ 1.13 |
| 7.5 kW | 1.25 kWh | R$ 1.25 |
Worked Example. Summer versus Winter End of Month Cost
Example only (use wattage for your specific model from your manual): let’s say “winter” runs at 5.5 kW and “summer” at 3.3 kW. One person showers for 10 minutes per day. Billing cycle is 30 days. Effective price is 1.00 R$/kWh.
| Setting | Power used / kW | Monthly usage / kWh | Cost/month in Reais (@1,00 R$) |
|---|---|---|---|
| Winter (hot / max power) | 5.5 | 27.5 | R$ 27.50 |
| Summer (warm / intermediate power) | 3.3 | 16.5 | R$ 16.50 |
Adapt this to your home: if your effective price is 0.90 R$.kWh, use 0.9 to convert the costs; if you take a shower for 12 minutes/day instead of 10, multiply the kWh by 1.2; if you have two people showering, multiply by two.
When to replace the heating element (and how to avoid burning it early)
Now what signs should you look out for that suggests it’s time to break out the plunger?
- Water is not heating up even when on the highest “hot” setting (most likely sign).
- Water is “semi-hot” on lower settings and “high” on maximum setting (floater tap operating on minimum floater tap through).
- Jumps/makes your breaker or RCD/DR flop whenever shower used (this might also suggest your shower unit is possibly earthing circuits so don’t assume it is only its element you need to worry about until you test properly).
- Your shower has either a brown patch, crack, “burnt smell” and/or looks corroded/eaten through – stop draining yourself out and do a real check!
Rule #1: buy the exact correct replacement part
Match the heating element you buy to your shower’s model and voltage (127 V vs 220 V, for example) and to the product’s power specification. Manufacturer manuals tell you to identify the correct element model for your shower before buying and to make replacements with the element specified for the correct power rating of the product.
General replacement checklist (high level)
- Turn off the shower’s circuit breaker at the panel before doing any work.
- Shut off water to the shower and relieve the pressure (briefly turn on the shower to drain).
- Open the unit as instructed in your manual and remove the element/cartridge.
- Install the new element/cartridge, properly seated as instructed in your model.
- Turn on the water to your shower to fill the heating chamber/cartridge before switching on the power to help avoid burning up the new element.
- Power on and check for leaks and normal operation.
Habits that help the element(s) last longer
- When in doubt always let cold water run before energizing (especially after a maintenance activity) to be sure the area being heated is full of water.
- Using the proper electrical connectors, Never install the shower at an outlet using a plug. (Follow the manual’s safety guidance).
- Make sure that the unit is electronically or physically grounded according to relevant standards and the manufacturer’s guidelines.
- If not an electronic temperature control type, close the water valve before changing temperature settings (then reopen).
Common Mistakes That Ruin Your Cost (or Create Failures)
- Assuming “maximum” wattage of shower for calculation of “summer” cost (often it’s in between max and min power). Check the manual and use the wattage for the set temperature if it’s available there.
- Using a “tariff without taxes/flags” dumped on a website instead of the one that appears on your bill that you actually pay per kWh.
- Getting the wrong voltage heating element (127 V vs 220 V) or wrong wattage” (“wrong” is the wattage the shower is rated for).
- Turning the power back on before running water through the shower after installing it or doing maintenance (this will burn out the element).
FAQ
Winter setting is always more expensive, right?
How do I calculate the power (kW) for the summer setting?
How do I get a realistic R$/kWh from my bill?
Can I change the temperature while showering?
Should I plan to “budget” to change the heating element, like regularly?
Referências
- Lorenzetti – Power ratings for showers tips FAQ: electric shower (intermediate power, grounding guidance)
- Lorenzetti – Century Digital installation manual (element replacement steps)
- Lorenzetti – Electric shower tips for installation and use (disconnect the breaker and water before changing the element, run water through then power up, temperature->)
- ANEEL – Tariffs and economic/financial tariff report/tool (official reference for tariff reports/tools)
- Enel – Explanation of TE and TUSD and how my kWh of electricity consumed during the month are billed in total
- Brazil Escola – Consumption, full problem (kWh = power × time) for worked example