Heat exchanger on Raypak

Lakedarlingresort

In The Industry
Jan 23, 2025
4
Alexandria, Minnesota
Pool Size
20000
Surface
Plaster
Chlorine
Liquid Chlorine
Hi, I’m new to this forum and I’m trying to figure out why my heat exchanger on my Raypak for both pool and spa are going out or bad after a years use having condensation run down the stacks and into the unit!!????
The heat exchanger are not chemically damaging themselves from the inside out. They’re being damaged and corroded acidic corrosion from the outside in causing Pine holes, and the condensation runs down the chimney stack out over the hood and down into the units, causing the flame and corrosion to not combust properly how to fix this please somebody Help me to fix this issue.
 
Have you contacted Raypak to see what they could do to help you?

Is all venting to code and per Raypak Instructions?

Who did the venting?

Do you have adequate ventilation and combustion air?

You might need a D-2 Power Vent Kit.

Another option for an installation that requires horizontal runs is the D-2 power vent kit option.

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NOTE: The D-2 Power Vent operates with a positive vent static pressure and with a vent gas temperature that prevents excessive condensate production in the vent, and as such, is a CATEGORY III appliance.

For more information consult the D-2 Power Vent manual, (P/N: 241243).

CATEGORY I vent material such as B-vent must not be used under CATEGORY III conditions.

The power vent system is a fan-assisted vent system designed for use on models 206A-406A.

The power vent system, when installed as directed, is capable of operating in applications such as through-thewall venting with reduced horizontal and vertical vent pipe sizes in new and current installations.

The unit is factorywired for 240 VAC, with capability of field-rewiring for 120 VAC.

For more information consult the D-2 Power Vent manual, (P/N: 241243).


 
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Sounds like an indoor unit with improper venting.

Have you had a Gas contractor or qualified HVAC Company review the installation?

What is the heater Model Number?

Pictures of the installation?
Yes, it’s a venting issue for sure. I’ll send pictures of our stack as it condensates so badly that it drips back down into the unit.
model number BR266AENCASME
 

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I think that you have too much horizontal run and you have a common vent, so those require specific Design, Engineering and Architecture.

Is the venting single wall or double wall?

Type “B” double-wall or equivalent vent pipe is recommended for natural draft.

Type B vent must not be used with Category III gas-fired appliances and must not be used on the discharge side of a power vented appliance.

You might need a D-2 Power Vent for each heater.

You need to find a good HVAC or otherwise qualified contractor and have them work with Raypak to get the correct Design, Engineering and Architecture.


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Flue materials must be certified to CATEGORY I or better.

Type “B” double-wall or equivalent vent pipe is recommended.

A draft of -0.01" to -0.08" WC must be maintained.

However, single-wall metal vent pipe may be used as specified in the latest edition of the National Flue Gas Code, ANSI Z223.1 (Canada - CAN/CSA-B149).
 
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BR266AENCASME

B= Bronze Header.
R = Raypak
266 = 266,000 btu/hr
A = Atmospheric
E = Electronic.
N = Natural Gas
C = Copper Heat Exchanger.
ASME = American Society of Mechanical Engineers

The Atmospheric Model does not have a fan and it might need an assist from a Power Vent.

The common vent is an additional complication and you need a good qualified contractor that knows how to safely handle a common vent with a pressure vent or maybe add a second vent so each has its own vent.

You also need to make sure that there is sufficient supply air for combustion.

You need to check the gas pressure static and dynamic.

A Power Vent will change the pressure from negative to positive, which requires a Category III vent, which allows pressure without leaks.

The B-R266A-EN-C is the model number for a Raypak Digital ASME Copper Natural Gas pool heater.

It's a 266K BTU heater that uses natural gas.

The ASME stands for American Society of Mechanical Engineers, which sets safety and performance standards for mechanical systems.

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Category III: A positive pressure, non-condensing gas appliance category

The D-2 Power Vent is a fan-assisted combustion system designed for application to heater models 206 thru 408.

When installed as directed, the unit is capable of operating in applications such as through-the-wall venting and reduced horizontal and vertical Category III flue pipe sizes in new and existing installations.

The D-2 Power Vent includes a blower with a 120/240 volt60Hz 1.95/1.0A 3200 RPM motor and a plenum, complete with a draft proving switch and a motor relay.

6. VENTING
The D-2 Power Vent operates with a positive vent static pressure and with a vent gas temperature that prevents excessive condensate production in the vent, and requires Category III venting.

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A Cat 1 gas-fired appliance is a negative pressure, atmospheric vent system.

This means that there is no fan or blower in the unit.

A natural draft, or convection current, is created simply because hot gasses rise.

Because there is negative pressure within the vent, the venting system isn't required to be gasketed or otherwise sealed.

Cat 3 appliances have an induced draft, which is created by a fan or blower.

This creates positive vent pressure.

Most manufacturers of Cat3 appliances require AL29-4C venting systems.

This is a stainless steel, gasketed vent material.

If a positive pressure vent isn't gasketed, flue gasses will leak into any space through which the flue passes.

 
I suspect that a lack of combustion supply air is contributing to the problem.

Is there a way for the room to get enough fresh air?

Also, chemicals like chlorine tabs, bromine tabs, muriatic acid etc. stored in the room will produce fumes that will get into the combustion process and cause corrosion.

Natural gas is a naturally occurring mixture of gaseous hydrocarbons consisting primarily of methane (95%).

The complete combustion of methane produces water and if the exhaust gets cool enough, the water condenses from gas vapor to liquid.

The water is very corrosive to the metal venting, copper heat exchanger and the burner tray tubes, which are likely also damaged.

Did you pull the burner tray?


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This is your problem-

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That’s an enormous cold surface area that’s acting basically like a condenser. The combustion gas from the heaters simply can not make it up the vent stack before the cold duct work turns it all back into liquid. I don’t think a powered vent would even help.

As @JamesW has pointed out with his many posts, you need a qualified HVAC company to come in, look at the specs for the heaters and completely rework that vent stack. Depending on how high the roof vent goes, you may need a powered draft fan at the roof exhaust.
 
With a power vent you can probably reduce the vent size, which reduces the surface area.

The vent can be insulated to maintain exhaust temp and a condensate trap can be installed.

In any case, you need a qualified contractor who is licensed and experienced to do the work.

They should consult with Raypak so that Raypak can give their input on proper Design, Engineering, Architecture, Materials and Installation.

The HVAC Contractor needs to communicate with Raypak because the Contractor should know the terms that a Raypak Technical Advisor will use.


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BR266AENCASME

B= Bronze Header.
R = Raypak
266 = 266,000 btu/hr
A = Atmospheric
E = Electronic.
N = Natural Gas
C = Copper Heat Exchanger.
ASME = American Society of Mechanical Engineers

The Atmospheric Model does not have a fan and it might need an assist from a Power Vent.
The Low NOx has a fan, but I think that it is still considered to be an "Atmospheric" Model because it has a negative draft pressure of -0.01 to -0.08" w.c.

Cat I appliances can also be FAN ASSISTED but that does not change as the fan is utilized to only bring in the combustion air.

A Category I appliance can be fan-assisted, but the fan's sole purpose in this case is to provide combustion air, not to actively draw flue gases out of the vent, as the appliance still relies on natural draft to vent the combustion products, which is the defining characteristic of a Category I appliance.

Category I definition:
A Category I appliance is a non-condensing gas appliance that operates with a non-positive vent static pressure, meaning it relies on natural draft to vent flue gases.
Fan-assisted in Cat I:
When a Category I appliance is "fan-assisted," it simply means a fan is used to actively draw in combustion air needed for burning the fuel, not to assist with exhausting the flue gases.

Category I Gas Appliance – An appliance that operates with negative static pressure in the vent and a temperature that is high enough to avoid condensation in vent. Comment: May be atmospheric or fan-assisted combustion; airtight vent connector is not required.

Category I Fan-Assisted Gas Appliance – An appliance that operates with negative static pressure in the vent, a temperature that is high enough to avoid condensation in vent, and an integral fan to draw a controlled amount of combustion supply air through the combustion chamber.

Comment: Airtight vent connector is not required; induced combustion fan installed by manufacturer.

Category III Gas Appliance – An appliance that operates with positive static pressure in the vent and a temperature that is high enough to avoid condensation in vent.

Comment: Airtight vent connector; vented through the wall; forced draft.


The Low NOx might have been a better choice, but you can also add the D-2 Power Vent Kit to the Low NOx Model.

Raypak might even recommend a different commercial heater for your particular system.

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Right now, you are Cat 1 (Non-Condensing Negative Draft), but you are getting condensation, which indicates a bad design.

You probably need to go to Cat 3 (Non-Condensing Positive Draft), which will probably require all new Venting that is airtight and made from better steel.

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Who installed the heaters?

When were the Heaters Installed?

Was the installation Permitted and Inspected?

Was the Installation "Commissioned"?

Is one heater for the pool and one for the spa?

If yes, what are the temperature set points for each?

Does one heater get more damage than the other?

Have you talked to the Installer to see what they can tell you?

Have you talked to Raypak to see what they can tell you?

 
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