Expert help that stays with you

Whether you’re choosing one component or planning the whole room, small details can become expensive problems once installation begins. We know the products we sell and the questions to ask early, helping catch mismatched components, overlooked requirements, and installation issues while they are still easy to fix.

Our job does not end when your order ships. We stay available through installation and beyond. If something needs attention, we stay involved, work the problem, and help see it through.

We want you to feel good about choosing Sauna Marketplace long after your first session, and confident recommending us to a friend. That standard guides the advice we give, the products we sell, and the way we take care of our customers.

Sauna and heater customers also receive free shipping on sauna accessories for life.

Planning a sauna, or need help with one you purchased from us? Our founders have assembled many of the saunas we sell, visited the manufacturers, and use these products every day. New customers and existing Sauna Marketplace sauna and heater owners can Book a Ben consultation.

Specs
Weight6.3 lbs
Dimensions8.5 × 19.5 × 2.25 in
ModelWaterEx
Part NumberH3009032
Included ComponentsWater-heat exchanger, Installation and operation manual, 5-Year limited warranty
Installation ManualInstallation Resources
Residential WarrantyLimited 5-Year Warranty
UPC4745090279511
Water tank connection3/4 in NPT male
Material0.2 in steel, coated with heat-resistant paint
Mounting positionsRear edge or sides of the stove
Includes

What Is Included

Includes the product and configuration selected above. Hardware, controls, stones, venting, and accessories are not included unless specifically listed.

See How It Fits for required and compatible products.

How It Fits

How This Product Fits the System

What it is used for

A heater-system accessory for the application shown above. Match the model, part number, dimensions, and installation instructions before ordering.

What to plan

  • Start with the heater, chimney, or control model—not brand alone—then confirm the accessory part number and configuration.
  • Optional accessories are not required unless the selected product or installation manual says otherwise.
  • Replacement and installation parts must follow the current system manual, clearances, and local code.

Products that use this item

This item is used by the following products.

Gallery

HUUM WaterEx | HIVE Wood Water Heat Exchanger

HUUM water heat exchanger for HIVE wood-burning sauna stoves. Heats water while the sauna is being heated, with 3/4 in NPT male pipes for the water tank. Mounts on the stove’s rear edge or on the sides.

Build Your Quote:

$211.00

Shipping

Free Shipping On Accessories
Valid for orders over $200, or for anyone who has ever purchased a sauna or heater on Sauna Marketplace.

Shop Saunas | Shop Sauna Heaters

Share your selected heater size and add-ons. Prices and availability are confirmed when the link is opened.

Zero Interest Payments:

Buy Now, Pay Later with premium financing packages only available on Sauna Marketplace.

Pay with HSA/FSA:

We teamed up with FLEX to make HSA/FSA payments easier than ever.

Built for

What’s included

  • Water-heat exchanger
  • Installation and operation manual

What it does

HUUM’s description: “A heat exchanger heats water when the sauna is heated. The heat exchanger is made of 0.2 in steel and coated with heat-resistant paint. The heat exchanger has ¾″ male pipes for connecting the heat exchanger to the water tank. The heat exchanger may be placed on the rear edge or on the sides.”

It uses heat the stove is already producing to warm a water supply during the same firing, rather than running a separate water heater.

Fitting it

  • For HIVE sauna stoves
  • 3/4 in NPT male water tank connection
  • Mounts on the stove’s rear edge or on the sides
  • 0.2 in steel, coated with heat-resistant paint

Which stove

The catalog lists WaterEx against the 17 kW HIVE Wood stove and appears under Operating Accessories on the HIVE Wood product page. The water tank itself is a separate item.

Specifications

Model WaterEx
Part number H3009032
UPC 4745090279511
Assembled dimensions 8.5 in x 19.5 in x 2.25 in
Water tank connection 3/4 in NPT male
Material 0.2 in steel, heat-resistant paint
Weight 6.3 lb

Common questions

How does a sauna stove water heat exchanger connect to a water tank?

The HUUM WaterEx connects to a water tank through 3/4 in NPT male pipes. HUUM: “The heat exchanger has ¾″ male pipes for connecting the heat exchanger to the water tank. The heat exchanger may be placed on the rear edge or on the sides.” The exchanger ships with its installation and operation manual; the water tank is a separate item.

What does a water heat exchanger do on a wood-burning sauna stove?

A water heat exchanger heats water off the stove's own fire, while the sauna is being heated, instead of running a separate water heater. HUUM's WaterEx is made of 0.2 in steel coated with heat-resistant paint and is designed for HIVE sauna stoves.

Where does the HUUM WaterEx mount on the stove?

The HUUM WaterEx may be placed on the rear edge of the stove or on the sides. It measures 8.5 in x 19.5 in x 2.25 in and weighs 6.3 lb, and The catalog lists against the 17 kW HIVE Wood stove.

Expert help that stays with you

Whether you’re choosing one component or planning the whole room, small details can become expensive problems once installation begins. We know the products we sell and the questions to ask early, helping catch mismatched components, overlooked requirements, and installation issues while they are still easy to fix.

Our job does not end when your order ships. We stay available through installation and beyond. If something needs attention, we stay involved, work the problem, and help see it through.

We want you to feel good about choosing Sauna Marketplace long after your first session, and confident recommending us to a friend. That standard guides the advice we give, the products we sell, and the way we take care of our customers.

Sauna and heater customers also receive free shipping on sauna accessories for life.

Planning a sauna, or need help with one you purchased from us? Our founders have assembled many of the saunas we sell, visited the manufacturers, and use these products every day. New customers and existing Sauna Marketplace sauna and heater owners can Book a Ben consultation.

Specs
Weight6.3 lbs
Dimensions8.5 × 19.5 × 2.25 in
ModelWaterEx
Part NumberH3009032
Included ComponentsWater-heat exchanger, Installation and operation manual, 5-Year limited warranty
Installation ManualInstallation Resources
Residential WarrantyLimited 5-Year Warranty
UPC4745090279511
Water tank connection3/4 in NPT male
Material0.2 in steel, coated with heat-resistant paint
Mounting positionsRear edge or sides of the stove
Includes

What Is Included

Includes the product and configuration selected above. Hardware, controls, stones, venting, and accessories are not included unless specifically listed.

See How It Fits for required and compatible products.

How It Fits

How This Product Fits the System

What it is used for

A heater-system accessory for the application shown above. Match the model, part number, dimensions, and installation instructions before ordering.

What to plan

  • Start with the heater, chimney, or control model—not brand alone—then confirm the accessory part number and configuration.
  • Optional accessories are not required unless the selected product or installation manual says otherwise.
  • Replacement and installation parts must follow the current system manual, clearances, and local code.

Products that use this item

This item is used by the following products.

Gallery

PLAN THE WHOLE SAUNA

The room and heater still have to work as one system.

Start with the room dimensions, then account for glass, masonry, insulation, ceiling height, required clearances, and available electrical service. That is how we move from a product that looks right to a sauna that heats evenly and comfortably.