When you want hot water quickly in your RV, waiting is not an option. The Apus RV tankless water heater claims to deliver hot water fast, but how fast is it really? Many RV owners wonder if it can match the comfort of a home water heater or if there are hidden delays. If you’re considering the Apus model or already own one, understanding how long it takes to heat water is key. In this article, you’ll learn exactly what affects heating speed, real-world timing, and how to optimize performance. We’ll also compare Apus with other tankless heaters, answer common questions, and clear up beginner mistakes. Whether you’re planning your next road trip or just want reliable showers, you’ll find practical answers here.
How The Apus Rv Tankless Water Heater Works
The Apus RV tankless water heater uses modern technology to heat water directly. Unlike traditional heaters with tanks, it does not store water. Instead, it heats cold water as it flows through the unit. When you turn on a faucet, the water passes over heating coils or a gas burner inside. This process is called on-demand heating.
Most Apus models use either propane gas or electricity. Gas models are popular because they deliver more hot water per minute and work well off-grid. Electric models are quieter and easier to install, but often have lower flow rates.
Key Features
- Instant heating: No waiting for a tank to fill and heat up.
- Compact design: Fits in small spaces, perfect for RVs.
- Energy efficient: Uses power only when needed.
- Adjustable settings: You can control water temperature.
Flow Rate And Temperature Rise
The main factors in heating speed are flow rate (how much water passes through per minute) and temperature rise (how much the unit can heat the incoming water). Apus heaters typically have flow rates between 1.5 and 3.0 gallons per minute (GPM). If incoming water is cold, the unit works harder, possibly slowing down or limiting temperature.
For example, if your Apus heater has a 2. 0 GPM rate and your tap is fully open, you’ll get two gallons of hot water per minute—assuming the heater can keep up.
What Affects Heating Time For The Apus Rv Tankless Water Heater?
Heating time is not just about the heater itself. Several factors impact how quickly you get hot water:
1. Distance From Heater To Tap
The farther your faucet or shower is from the heater, the longer it takes for hot water to reach you. The pipes fill with cold water first, then hot water pushes through. In most RVs, this delay is short—usually 5 to 15 seconds.
2. Water Flow Rate
If you open the tap fully, water moves faster through the pipes. However, if the flow rate is too high, the heater may not be able to raise the water temperature as much. Many Apus owners find the best results at moderate flow rates.
3. Incoming Water Temperature
Cold climates or winter RVing mean your water starts colder. The heater needs more energy and time to reach your desired temperature. For example, if the incoming water is 45°F, and you want 105°F, the heater must raise the temperature by 60°F.
4. Heater Power (btu Or Kw)
Gas models use BTU (British Thermal Units) to rate heating power. Electric models use kilowatts (kW). Higher numbers mean faster heating. Typical Apus gas heaters run between 10,000 to 40,000 BTU.
5. Water Pressure
Low water pressure slows down flow, giving the heater more time to heat the water—but it also means weaker showers. If pressure is too high, water may pass too quickly and not heat fully.
6. User Settings
Apus heaters often have temperature controls. If you set a lower temperature, the heater needs less time and energy. Setting it higher means more work for the heater.
7. Maintenance And Age
Older heaters or units with mineral buildup heat water more slowly. Regular maintenance helps keep your Apus heater running efficiently.
Real-world Example
Imagine you’re parked in a cool area, with incoming water at 55°F. You set the heater to 105°F, and the flow rate is 2.0 GPM. The Apus heater needs to raise the temperature by 50°F. With a 36,000 BTU unit, you’ll get hot water in about 6–12 seconds after turning on the tap, depending on pipe length.
Typical Heating Time For Apus Rv Tankless Water Heater
Let’s Get Specific. How Long Does It Really Take?
Startup Delay
When you turn on the tap, the Apus heater senses the water flow and activates. This takes 1–3 seconds. Next, the heating element or burner starts warming the water.
Pipe Transit Time
Hot water must travel from the heater to your tap. In most RVs, pipe length is short, so 5–15 seconds is common. If your heater is next to the shower, this can drop to 3–8 seconds.
Total Time
- Average time to get hot water at the tap: 6–20 seconds
- For showers: 10–25 seconds
- For kitchen sinks: 6–15 seconds
Factors That Change This
- Colder weather: Adds 2–5 seconds
- Low flow rate: Adds 1–3 seconds
- Longer pipes: Adds 5–10 seconds
Data Comparison Table
Here’s a simple comparison of heating times across different Apus models and situations:
| Model | BTU/kW | Flow Rate (GPM) | Heating Time (Seconds) | Notes |
|---|---|---|---|---|
| Apus 10P Gas | 20,000 BTU | 1.5 | 12–18 | Good for small RVs |
| Apus 14E Electric | 4.5 kW | 2.0 | 8–16 | Works well in mild climates |
| Apus 18P Gas | 36,000 BTU | 2.5 | 6–12 | Fastest heating |
Non-obvious Insight
Beginners often overlook the startup delay. The heater doesn’t heat instantly—it waits for water flow, then starts heating. Also, the first water you get is always cold (from pipes), so even the best tankless heater needs time for hot water to arrive.
Comparing Apus With Other Rv Tankless Heaters
If you’re shopping for an RV water heater, it helps to see how Apus compares to other brands. Let’s look at heating time, flow rate, and energy efficiency.
Heating Time Comparison Table
| Brand | Heating Time (Seconds) | Max Flow Rate (GPM) | Energy Source |
|---|---|---|---|
| Apus | 6–20 | 2.5 | Gas/Electric |
| Girard | 8–18 | 2.4 | Gas |
| Truma | 7–16 | 2.6 | Gas/Electric |
| Suburban | 10–22 | 2.0 | Gas |
Apus heating times are among the fastest. Truma and Girard are close, but Suburban tends to be a bit slower, especially in colder conditions.
Flow Rate Differences
Most RV tankless heaters have similar flow rates, between 1. 5 and 2. 6 GPM. Apus models stand out for delivering consistent hot water even at higher flow rates.
Energy Efficiency
Apus is known for energy-efficient design, using less propane or electricity for the same amount of hot water. This is important for RV users who want to conserve resources.
Example: Apus Vs. Girard
An Apus 18P (36,000 BTU) delivers hot water in 6–12 seconds at 2.5 GPM. The Girard GSWH-2, with similar power, takes 8–18 seconds. For a quick shower, Apus may save you several seconds, especially in cold weather.
Non-obvious Insight
Many buyers focus on maximum flow rate but forget to check minimum activation flow (the least amount of water flow needed to turn on the heater). If you use low-flow shower heads, Apus units often activate sooner than others, giving you hot water even when saving water.
Practical Tips To Speed Up Heating Time
Want to get hot water faster? Try these strategies:
- Insulate pipes: Wrap pipes with foam insulation to keep water warmer and reduce waiting time.
- Shorten pipe runs: If possible, place the heater closer to your main water use (like the shower).
- Use moderate flow rates: Don’t open the tap fully—find the sweet spot where water is hot and flow is comfortable.
- Pre-run the tap: Let water run for a few seconds before showering; this clears cold water from pipes.
- Maintain your heater: Clean filters and descale the unit to keep heating speed high.
- Adjust temperature settings: Lower settings mean faster heating and less energy use.
Example
If you insulate your pipes and set the heater closer to the shower, you can cut the time to hot water by 5–8 seconds. For frequent shower users, this can add up.
Common Mistakes Beginners Make
Not understanding the Apus heater’s process can lead to frustration. Here are mistakes to avoid:
- Expecting instant hot water: Even tankless heaters need a few seconds to heat and deliver water.
- Opening taps too quickly: High flow rates can drop water temperature.
- Ignoring minimum flow: If your tap is barely open, the heater may not activate.
- Poor maintenance: Mineral buildup slows heating.
- Setting temperature too high: The heater works harder, increasing delay.
Non-obvious Insight
Some RV owners install low-flow faucets to save water, but this can cause the heater to fail to activate. Check your Apus model’s minimum flow requirement before changing fixtures.
Real-world User Experiences
Let’s look at what actual RV owners say about Apus heaters:
- “I get hot water in about 10 seconds after turning on the shower. It’s much faster than my old tank heater.”
- “In winter, the delay goes up, but still less than 20 seconds. I insulated my pipes, and it helped.”
- “My kitchen tap is close to the heater, so hot water arrives in 6 seconds. For the bathroom, it’s more like 15 seconds.”
Some report problems when water pressure is low, or when using the heater in very cold climates. Most users recommend regular cleaning and checking propane levels for consistent performance.
How To Choose The Right Apus Model
If heating time is your main concern, focus on these factors:
1. Btu Or Kw Rating
Higher BTU or kW means faster heating and higher flow rates.
2. Installation Location
Choose a spot close to your main faucet or shower to reduce pipe transit time.
3. Climate
If you travel in colder regions, pick a model with higher power and good insulation.
4. Water Pressure
Check your RV’s water pressure and make sure the heater can handle it.
5. Minimum Flow Activation
If you use low-flow fixtures, make sure the heater activates at low flow rates.
Buying Mistakes
- Choosing a model with too low BTU/kW for your needs
- Ignoring climate conditions
- Installing far from main water usage points
Comparison Table: Apus Models
| Model | BTU/kW | Heating Time | Best For |
|---|---|---|---|
| 10P Gas | 20,000 BTU | 12–18 sec | Small RVs, mild climates |
| 14E Electric | 4.5 kW | 8–16 sec | Urban camping |
| 18P Gas | 36,000 BTU | 6–12 sec | Cold climates, frequent showers |
Maintenance And Troubleshooting
Regular maintenance keeps heating times low. Here’s what to do:
- Clean filters every 3–6 months
- Descale heating elements if you use hard water
- Check for leaks in pipes and connections
- Inspect propane lines for gas models
- Test water pressure and adjust as needed
Troubleshooting Slow Heating
If you notice delays:
- Check for mineral buildup
- Ensure pipes are not too long or exposed to cold
- Confirm heater is set to proper temperature
- Verify water pressure is adequate
If problems persist, contact Apus customer support or check their official site for guides.
Environmental Impact And Efficiency
Tankless heaters are more efficient than tank models. Apus claims up to 30% energy savings compared to traditional heaters. Less propane or electricity used means lower emissions and longer RV battery life.
If you care about the environment, Apus is a smart choice. For more on tankless water heaters and efficiency, see Energy.gov.
Frequently Asked Questions
How Long Does It Take For The Apus Rv Tankless Water Heater To Heat Water?
Most Apus models deliver hot water at the tap in 6–20 seconds. The exact time depends on pipe length, flow rate, incoming water temperature, and heater power.
Can The Apus Heater Provide Hot Water For Multiple Taps At The Same Time?
Yes, but the total flow rate is divided. If you run two taps, each may get less hot water, and the temperature can drop if the combined flow exceeds the heater’s max rate.
What Is The Minimum Flow Rate Needed For Apus Heaters To Activate?
Most Apus units require 0.5–0.7 GPM to turn on. If your tap is open less than this, the heater may not start.
Does Cold Weather Slow Down Heating Time?
Yes, colder incoming water means the heater must work harder. Expect delays of 2–5 seconds longer in winter or cold climates.
How Often Should I Maintain My Apus Rv Tankless Water Heater?
Clean filters and descale heating elements every 3–6 months. Regular maintenance keeps heating times fast and avoids breakdowns.
RV life should be comfortable, and the Apus RV tankless water heater makes hot water easy. While it’s not truly instant, waiting less than 20 seconds for a hot shower feels almost luxurious on the road. With the right installation, maintenance, and model selection, you can enjoy reliable, fast hot water wherever you travel. If you’re new to tankless heaters, remember the startup delay, optimize your setup, and follow the tips above. With Apus, your journey is warmer and more efficient.
