800 Gallon Non-pressurized Buffer Tank


800 Gallon Commercial Solar Hot Water Storage Tank

SKU: StorMaxx-NP-0800G-6FT Category:
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How do I order? 

  • Orders can be placed online using the online ordering system. Our office will contact you to confirm your order, shipping details, and payment.
  • SunMaxx Solar is a manufacturer of solar hot water equipment, availability and production lead-times vary based on our production order queue

Manufacture Direct Pricing

Please note the referenced prices online are for manufacturer direct pricing only. For wholesale & distribution inquires, please contact our office for an offer.

Want to speak with our office? Call us 1-877-786-6299


The Non-pressurized Commercial Solar Hot Water Storage Tanks are perfect for Large Domestic Hot Water Preheating applications and can be used for small radiant/space heating applications for residential commercial and municipal locations.

Due to their special construction and design these Commercial Solar Hot Water Storage Tanks are able to be shipped within a crate that is only 18 inches wide allowing them to be easily delivered to and maneuvered around almost any work site – simple on site tank assembly is required.
Commercial Solar Hot Water Storage Tanks are available with a number of internal copper coil heat exchangers designed to meet the needs of nearly any solar water heating application need to be bought separately!

Need Assistance?
If you have questions need help or simply feel uncomfortable placing your order online feel free to contact the product representative at 1-800-786-0329.

StorMaxx™ NP Tank Features

  • Suitable up to 20 collectors ~ 580 ft2 required
  • Max 5 heat exchanger inside the tank
  • Standard sensor ports for all tanks – see in tech. specification
  • Solar & Ice Storage Buffer Tank

  • Perfect for Large DHW Preheating and for small radiant/space heating
  • Foldable design, easy to transport and move through standard 32″ doors
  • Possibility to designate port locations for the manufacture of your tank
  • Water fill port at the top of the tank (1″) included

  • Tanks made in USA
  • Heat exchangers made in USA

What parts & accessories do I need?

Heat exchangers are not included with a tank. They must be purchased separately. For the assistance please call our sales representative.

StorMaxx™ NP Port Location Guide

Possibility of designing port locations for the manufacture of your tank.
Please use the information below to complete the diagram. StorMaxx™ NP Port Location Worksheet can be downloaded in Downloads & Datasheet section down below the page.

The image on right represents three diagrams of an NP tank. You will be writing on the EXTERNAL TANK SURFACE diagram to designate port locations for the manufacture of your tank. Please use the information below to complete the diagram.

Sensor Ports
Sensor ports are standard on all tanks. All 4’ tall tanks get 2 sensor ports, one 2” below the water level, and one 2” above the water base. All tanks taller than 4’ get a third sensor port centered between the other two. Sensor ports are placed near requested piping ports unless otherwise specified.

Piping Ports
You must choose the ports you want installed in the tank and specify their locations. Above water level pass-throughs should be placed on the blue line. Available ports are listed in the chart below. On the EXTERNAL TANK SURFACE diagram, draw a circle where you want each port, and write the letter code from the chart below in the circle designating the port type. If you want your below water level ports at specific heights, write the measurements on the diagram.

Above Water Level Ports
Available PVC Pass-Throughs

CodeDiameter (in)Suitable for:
A13/4" copper
B1-1/41" copper, 3/4" SS flex
C1-1/21-1/4" copper, 1" SS flex
D21-1/2" copper
port location

Technical Details

Technical details

  • Max Temperature: 180 °F
  • Dimensions: 63in x 72in (D x H)
  • Weight: 281 lbs
  • Construction: Round, 0.032 embossed aluminum
  • Wall Material: EPDM Liner
  • Cover sheet: Aluminum
  • Insulation Material: Rigid R14 isocyanurate foam
  • Tank Sizes: 150 – 5000 gal

For the technical details please see the StorMaxx data sheet in Downloads & Datasheet section.

Technical Features:

  • Suitable for installation in Category E; For engineering calculations, please contact our engineering team for consulting services.
  • Seismic Cleats allow for installation of tanks in seismic zones
  • For HX Sizing: Please contact SunMaxx engineering for proper sizing.
  • Folded construction: tanks fit easily through standard doorways and other openings
  • Both tanks and heat exchangers are made in USA

The technical drawings presented below show placement of pipe pass-through ports, sensors, number of water coil heat exchangers, solar loop heat exchangers and the mounting of the tank to the surface. Please contact our Engineering Department for more information regarding custom designs.

np mount1
np mount2
Sunmaxx Solar tanks are typically used to pre-heat to an existing primary tank. This solutions has some advantages and its definitely more effective than installation the integrated heat source inside the solar tank. Pre-heating help to reduce the heat loses and price of electricity bills. The main factor of this solution is efficiency .
Yes you can. But we are recommending to use dedicated parts to our installations. All products can be easily connected using the SunMaxx Solar products. Moreover they we designed to different type of connections. Changing the parts and system installation may led to some problems or improper way of working the system.  If it is not enough for you , call us we will help you.
Optional parts are highlighted in each product sections on product site. Buying a tank is a piece of whole installation, there a some products like piping system, connection between them and collectors. The size of this elements should be chosen in a right way, suitable  to installation and customer requirements. Number of additional parts depends on a size of installation and type of building. If you have more direct questions, don't hesitate to contact us. The engineering team definitely helps you.

The StorMaxx Series include four types of solar tanks, which area designed for all working area form small to huge installations.


SE Series

Small solar tank designed for residential systems suitable max. for 3 collectors. Every tank include additional electric heater (4500 W), which can be used to heating a water if its needed. These tank have long life, so the will be higher return in investments.

CTEC Series

Solar tank suitable for combined systems (6 ports for supply , stratification and re-circulation). The tank has an easy installation process and removable insulation in order to fit in a 32 inch entry ways. In this tank it is possible to apply up to 3 heat exchangers. Suitable for large residential installation or small commercial installation.

ETEC Series

Solar tank are suitable for storage of hot water without contamination and has long-life time due to special material SUS 316L inner material. It also has a excellent thermal performance and there is a possibility to add an incorporated electric heater.

Non-Pressurized Series

Commercial/Industrial Solar Hot Water tanks which can be used in huge installations (volume 50-5000 G). The heat exchanger is not included - bought separately. Tanks are made in the USA and there is a possibility to add up to 12 heat exchangers. These tanks can store large amount of solar energy at low temperatures, which reduce costs and improve the overall performance of the system.

The volume of storage tanks depends on type of tank.  Every tank is different and has own advantage in specific area (domestic, commercial, industrial). In our offer you can find small tank for domestic usage to the huge tanks which can be used for industrial projects. Standard store tank volume depending of the number of people:
  • for 2-4 people - 80 Gallons
  • for 3-6 people - 120 Gallons
If there will be more direct question, don't hesitate to contact to the engineering team. The volume of the tank starts form 50 gallons  to 5000 gallons. Everyone will find suitable tank for own needs.
There are some variables which determine the right size of solar tank:
  • Annual Heating Costs
  • Number Of Collectors Installed
  • Water Consumption Daily/ Weekly/ Monthly
  • Required Water Temperature
  • Space Availability
If you need more information you can contact the engineering team, they help to you to choose right tank or ask some additional questions.
In our offer there are two series StorMaxx SE and StorMaxx ETEC, which have an possibility to provide additional heat form electric heat exchanger.  These solutions are used in situation, when the water temperature is under the expectations. This system helps solar system to heat water inside the tank using the electric power.
The dimensions depends on a type/model of the tank. Before you start, check on the website the dimensions of tank which you choose. Every parameter is included (diameter, height ) in the tank features and also in the specification.  These dimension can help you to check/measure the space availability for your new tank.


  • 7 years limited on tank and coil heat exchanger
  • 3 years limited on tank and coil heat exchanger in all commercial installations