Electric mini boiler plumbing

This is a electric mini boiler in floor heat system. It responded fine to normal operating controls. However, there no expansion tank, no tpr discharge pipe, theres a condensate hose that runs up and over everything. I can’t find install instructions to verify. Do any of you plumbers see any red flags?


It would be best for you to just state in your report what you see and refer repairs or evaluation to a licensed plumbing contractor.

If you are going to describe that clear tube as a condensate hose it was a good thing there wasn’t an installation manual around for you to read.

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Referred to as Hydronic Radiant Heating System.
That Hydronic Radiant Heating System has 6 Zone Loops.
Lower manifold in Blue is supply Upper Red manifold is return.
Model and serial number please.

Next time, look around any HVAC equipment for equipment data material.
Your questions could have been read in the papers/documents lodged above the boiler between a circuit cable and OSB sheathing.

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I think you got those flipped around according to the temperature gage on the manifolds and pump orientation. UPS26-99FC, 3-Speed Circulator Pump,

I checked for install paperwork, those sheets are for thermostat unfortunately.

Lol yes I know that standard is to refer a plumber. I’m here to learn something, so I can continue to learn and do my job better.

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You said you couldn’t find the installation manual. It took me about 10 seconds on Google search to find it. That’s why it’s important to always post model numbers and make with your question.


Yes I can Google. I like to learn from multiple sources. Especially pros who don’t need the manual. I find their expertise more valuable.


New one on me.

Lol really? If you install vinyl siding everyday I imagine you don’t need the instructions after a while…

The problem with installing boilers is the manual will come with 4 to 6 different methods of installing their equipment. You would be very surprised how different the installations are. Every manufacture has a proprietary method of installation. Someday download the installation manual for a modern condensate boiler and you’ll see what I’m talking about.

I have a feeling I made more than a siding installer as a licensed plumbing contractor😁

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But are you making more as an inspector than when you were a plumber :smiley:

Nope, my wife said I made hooker money. I’m semi retired now so it’s not about the money.

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I’m afraid to ask :face_with_raised_eyebrow:

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Update: My HVAC guy said the pvc looks like a makeshift pressure tank. The way it’s set up, it’s no longer a closed system and the black pipe will rust. Tpr needs discharge to the floor. Obviously not installed per manufactures instructions.

Applied Research Laboratories Inc. Electro Industries EMB-H-9 - 9 kW - 31K BTU - Hot Water Electric Boiler - 240V - 1 Phase.
Installation manual provided in the link above.
Best of luck with your endeavors, Ryan.
As home inspectors, we all started somewhere. It’s about being humble and what we learned along the way that makes us better.
Kind regards.
Robert Young


Happy for you in several regards. You have someone to share life with and have the good fortune of being able to semi retire.
Keep well.

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Thank you Robert. Hard work and discipline are the ingredients that paid off for me.

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It may be best to get a licensed plumber familiar with hydronic heating instead of an HVAC guy. I agree the large pipe looks like a makeshift expansion tank. It is very typical to have iron pipe in even a modern day condenser boiler installation. The pump is cast-iron, the air scoop is cast-iron and often the nipples used to connect the threaded adapters are going to be black steel.

This is why modern boilers come with rust inhibitor for start up. I’m just going to give you an example of what may happen if you mention in your report replacing the iron parts. A plumber comes in spends eight hours tearing down the system and replacing the parts with brass because you recommended no iron in the system. Remember just an example. The cost $1500. Owner gets a bid just for curiosity from a plumber familiar with hydronic systems and said this wasn’t necessary. Now who is going to be on the hook for the $1500?

Even state of the art modern commercial hydronic systems use black steel pipe that is either welded or connected with Victaulic couplings. The same thing with commercial chiller piping.

Just my two cents but get a plumber licensed for hydronic heating to look at the system. I had a hydronic license in the last state I lived in. If your HVAC guy is licensed in hydronic‘s he may need to become more familiar with modern boiler installation.

From the installation instructions Robert provided you.


  1. Unless the source water is unusually poor and/or rust elements, additives are not required. It is recommended the water source as shown on drawing BX305 comes through the household water softener.
  2. Impurities within a closed loop hydronics boiler are considerably less damaging than the typical domestic water heater. In a closed loop electric boiler, the water impurities “boil out” and the system essentially reverts to pure water. As a closed system, this “pure water” becomes the operating mode. In the case of domestic water tank, there is always new water entering with new impurities.
  3. However, if additives are required, use the recommendations and source from your local professional plumber, specializing in hydronics heating systems.