430 type Stainless Steel (including the front of the heater!)
Output based on 2500ltr (1000ltr in the brackets)
|Metal thickness||2 mm||2 mm||2 mm|
|Height||680 mm||680 mm||680 mm|
|Length||550 mm||700 mm||850 mm|
|Width||480 mm||480 mm||480 mm|
|Weight||45 kg||55 kg||70 kg|
|Chimney height||2×1 m||2×1 m||2×1 m|
|Chamber Length||450 mm||550 mm||600 mm|
|Power||15 kW (37.5kW)||19,5 kW (48.75kW)||23,5 kW (58.75kW)|
Glass door + £59
Chimney heat guard +£99
Output / input connection diameter: 50mm
Material: Stainless steel (AISI 430 2-3mm);
Medium size upgrade +£150
Large size upgreade +£300
Please note, that we can also make the heaters from different stainless steel metal grade if needed.
Category 430 stainless steel is most often used in hot tub production. No chlorine can be used with this type, as in long term it may damage the metal.
Category 304 stainless steel is non-magnetic. Small amounts of chlorine can be used with this kind of stainless steel. £115 extra
Category 316 stainless steel is most often used in sea water based equipment. Out of three categories, this stainless steel has the best corrosion resistant properties. It is also resistant to higher temperatures. £295 extra.
External wood fired heater advantages:
- External heater saves space in the hot tub, so you can choose a smaller hot tub for the same amount of people.
- Easy cleaning and burning.
Please note: We no longer make aluminium heaters and we only supply stainless steel heaters due to their better durability !
You will probably already know whether you’re looking for an internal or external unit, but you may not be familiar with the pros and cons of stainless steel versus aluminium. This is an important consideration not to be overlooked. Aluminium is cheaper and offer a great price/quality ratio, as well as being slightly lighter and heating the water faster. However, stainless steel stoves sturdier and better suited for the tests of time and nature, which makes them the better option if longevity is an important consideration.
Chloride / Chlorine levels and Stainless Steel alloy Selection
The 304 and 304L (18-8 alloys) have been utilized very successfully in fresh waters containing low levels of chloride ion of up to 100 ppm. This level of chloride is considered to be the limit for the 18-8 alloys, particularly if crevices are present. Higher levels of chloride might cause crevice corrosion and pitting. The 18-8 alloys are not recommended for exposure to marine environments which have much higher levels of chloride.
The resistance of the stabilized Alloys 321 to pitting and crevice corrosion in the presence of chloride ion is similar to that of Alloy 304 or 304L stainless steels because of similar chromium content. And therefore 100 ppm chloride in aqueous environments is considered to be the limit for the stabilized alloys, particularly if crevices are present.
For more severe conditions of higher chloride level, lower pH and/or higher temperatures, alloys with Mo (molybdenum), such as Alloy 316, should be considered. The Mo-bearing Alloy 316 and Alloy 316L may handle waters with up to about 2000 ppm of chloride.
Another factor to consider is the amount of free Chlorine (Cl2) (usually derived from sodium hypochlorite) which is added to water (well water, drinking water, swimming pool water, etc.) to kill bacteria. Cl2 (chlorine) is a very potent oxidizer (reason it kills bacteria) and therefore high levels of Chlorine may accelerate chloride corrosion of stainless steels. 304 and 304L, 321 SS may be used for “water applications” with up to 2 ppm chlorine, while 316 and 316L alloys may “take” up to 4 ppm.
Disclaimer: The info presented here has been compiled from sources believed to be reliable. No guarantee is implied or expressly stated here and the data given is intended as a guide only.