Hot Water System Plan

The Hot Water System Plan outlines how hot water will be generated, distributed, and integrated into the overall plumbing system of the CTC build.
The system is designed to support two possible heater configurations located in the garage: an on-demand gas water heater or a 10–20 gallon electric tank-style water heater.
This plan ensures that either option can be implemented cleanly without redesigning the plumbing system.

System Overview

The hot water system is built around three core goals:

Reliable hot water delivery to the bathroom and kitchen fixtures.
Future flexibility to support either a gas or electric water heater.
Clean integration with the cold water manifold and overall plumbing architecture.

All hot water originates in the garage area, where the heater will be installed.
From there, a dedicated hot water line supplies the bathroom shower, bathroom sink, kitchen sink, and optionally the passenger-side exterior outlet.

Heater Options

Option 1: On-Demand Gas Water Heater

If a gas on-demand heater is selected, it will be supplied by the house propane system (Tank 1) via the future-ready propane branch installed during the propane system build.

Fuel Source: Propane from Tank 1 (house system).
Location: Mounted in the garage with proper ventilation.
Advantages: Unlimited hot water, compact size, fast recovery.
Considerations: Requires propane routing, venting, and combustion air clearance.

Option 2: Electric Tank Water Heater (10–20 Gallon)

If an electric tank-style heater is selected, the propane branch to the garage will remain capped and unused.

Fuel Source: 120V or 240V electrical supply (depending on model).
Location: Mounted in the garage with drain pan and overflow protection.
Advantages: Simple installation, no combustion, quiet operation.
Considerations: Requires electrical capacity and longer recovery time.

System Components

Cold Water Feed: Supplied from the bathroom cold water manifold.
Hot Water Heater: Gas on-demand or electric tank (garage).
Hot Water Manifold: Distributes hot water to all fixtures.
Hot Water Lines: Routed to bathroom shower, bathroom sink, kitchen sink, and optional passenger-side outlet.
Pressure Relief Valve: Required for both heater types.
Drain Pan (Electric Tank): Recommended for garage installation.

Hot Water System Layout (ASCII)

Garage Area
┌───────────────────────────────────────────────┐
│                                               │
│   ┌───────────────────────────────┐           │
│   │  Hot Water Heater (Gas or     │           │
│   │  Electric Tank)               │           │
│   └──────────────┬───────────────┘           │
│                  │ Hot Water Output           │
│   ┌──────────────▼───────────────┐           │
│   │     Hot Water Manifold       │───────────────► Bathroom Shower
│   └──────────────┬───────────────┘           │
│                  │                           └──► Bathroom Sink
│                  │
│                  └──────────────────────────────► Kitchen Sink
│
│   (Optional) Hot Water Branch ─────────────────► Passenger-Side Outlet
└───────────────────────────────────────────────┘

Routing Strategy

The hot water routing is designed for efficiency, freeze protection, and minimal heat loss.

Short runs: The bathroom receives hot water quickly due to proximity to the garage.
Insulated lines: All hot water lines are insulated to reduce heat loss.
Protected routing: Lines run inside conditioned space whenever possible.
Optional branch: Passenger-side outlet can receive hot water if desired.

Installation Notes

Mounting: Secure heater to garage framing with vibration-resistant hardware.
Drainage: Provide a drain pan and overflow route for electric tank heaters.
Venting (Gas): Follow manufacturer requirements for exhaust and combustion air.
Electrical (Electric Tank): Ensure proper breaker size and wiring.
Pressure Relief Valve: Route discharge line safely to the exterior or drain pan.
Leak Testing: Test all hot water lines under pressure before closing walls.

Integration With the Plumbing System

The hot water system integrates with the larger plumbing system as follows:

Cold Water: Bathroom manifold → Heater → Hot water manifold → Fixtures
Hot Water: Heater → Bathroom → Kitchen → Optional passenger-side outlet
Grey Water: All hot water fixtures drain into their respective grey systems

How This Plan Will Evolve

Once the final water heater type is selected, this plan will be updated with exact specifications, mounting details, electrical or propane requirements, and installation photos.
The system is intentionally designed to support either heater type without requiring changes to the plumbing architecture.