Automotive Antifreeze/Coolant for Boiler Heating System??

[joepar]

In a gas fired boiler heating system (home), can I use automotive Antifreeze/Coolant in place of the plumbing industry product?
It seems to me that the properties required in this product is well contained in the auto product as well and 75% cheaper in price. My system consists of radiant floor heating with the use of 'Grey Pipe' and cast iron boiler.
I've pulled out the boiler to fix a leaky pipe joint and flushed the system with tap water at full flow. I also separately flushed the boiler. Before installing the boiler, I would like to inject the necessary chemical that contains inhibitors for rust, corrosion and foam to help protect the boiler and keep the system operating efficiently.
So the question is, would I damage any part of the system if I use a quality grade of automotive Antifreeze/Coolant ? Appreciate your response. I live in British Columbia, Canada.
Thanks. Joe

 

[breezer]

anti freeze indoors

 

[oilman]

You would need to know what is in the automotive product and compare with the plumbing product before comparing prices.

Automotive AF is likely to be ethylene glycol, or perhaps ethanol. The plumbing version is more likely to be propylene glycol which is much less toxic. Toxicisity is important in case you have a leak in the system causing primary water to leak into the secondary water with disasterous results. Your heating system might survive, but would the occupants?

You'll need to do the currency conversion yourself, but the plumbing product may cost less than £1.00 a week to protect your system

 

[joepar]

Thanks for your response. The fresh water supply are both equipped with one way check valves to prevent back flow into the tap water system.
Onse loaded, the radiant system is a closed system heated through a heat exchanger. Would the Boiler product not be just as toxic in terms of contaminating tap water?
As part of my job, I'll remove and test the check valves' for proper function.
Anyone out there familiar with the composition of the product for boilers heating versus the automotive AF?

 

[oilman]

Propylene glycol based antifreeze is, as far as I can tell, described as "food grade" antifreeze, make of this what you will as far as toxicisity is concerned. There is also the problem of the additives. These are corrosion inhibitors, and as an example nitrite type inhibitors are rather nasty.

The leaks I referred to are the leaks from breakdown of the system, such as the heat exchanger in a combi, or the coil in a tank.

Check valves are a totally different animal. In the UK we are not allowed to rely on any amount of check valves to prevent system water coming into contact with potable water. See this before you drink. The unreliability of check valves is why we have to have a filling loop for sealed systems, which should be disconnected to guarantee the integrity of the water supply. We could daisy chain 100 check valves and it still would not meet the regulations.

There are plenty of people out "there" or even "here" who know about antifreeze for other than automotive use, I suggest you search the internet, and do a bit of "independent" research. A lot that most of us here know is what we find out by doing just that.

For the sake of a few more pounds, you can have an antifreeze that has been designed to be used in heating systems. These systems are expected to last decades if looked after. Vehicles are expected to last years.

I find it interesting to research these things, but if I was doing it for a living, it would already have cost you more for that than you would have to pay extra for the right stuff.

I would not like to be in your shoes if you have a leak in your system and somebody in your house ingests some water. It just could be fatal (but then think of the savings)

 

[joepar]

Thank you for your contribution.
If it were not for check valves, the fluid control engineers could never design a system that works. Aside from check valves, the street water pressure runs approximately 75psi which is reduced to 18psi by a pressure reducing valve on the line to the boiler system. So back up would be virtually remote and only when the street pressure drops or flow shut down.
I'm an aircraft mechanic by training and I've worked in the oil industry for 40 years. I've found that many manufacturers rebrand and repackage the same product line if it is going to be used for the same or similar purpose. The automotive industry development continues to challenge manufacturers of the fluids they require, so I believe that the automotive product would be superior and is only less expensive because of the extremely competitive market. The plumbing industry on the other hand is essentially kept as a 'closed club' of plumbers considered to be 'specialists' and who invariably charge more that an doctor's house call.

You should know the life of car engines are not measured by time. Engines have a lot of moving parts that wear and is not standing still just circulating hot water. My motive is not only cost but quality. In the automotive industry, the engine that needs to be protected can cost upwards from US$4,000 to $10,000 while a new boiler would cost $1,000.
BTW, I don't know of boilers that last for decades. I'd appreciate knowing the make of the type you speak of.

Again, I thank you for your input but do not appreciate the sarcasm.

 

[oilman]

Engines have a lot of moving parts that wear and is not standing still just circulating hot water.

The moving parts don't come into contact with water, with the exception of the thermostat and the water pump, rather like a central heating system.

CH systems have worse electro-chemical chacteristics than vehicles, ie steel+copper+steel+copper+steel+copper etc.

Stewart, Trianco, Wilson, Thorn, (in the UK) and others. All of these boilers I have see at 20, 30, and 40 years old and they're still working.

The check valves used in plumbing systems are very low cost compared with their industrial counter parts. I am surprised you don't seem to have regulations to control the configuration of heating systems.I assume you have looked at the link regarding backflow in water supplies? With your experience you will know that problems don't occur when things go right, but when they go wrong, and as an example (for whatever reason) just look at the rudder control valves on the Boeing 737.

With your extensive experience in the aircraft and automotive industry you will know of the amount of development work that goes into products, I am also aware of the marketing devices used by companies, but the automotive antifreeze manufacturers don't expect their products to come into contact with water that people might ingest.

I have an engineering history that is much wider than just the heating industry, but I don't see that that is relevant.

If you want to use an automotive product, it might be worth asking a manufacturer if they would recommend it's use for domestic heating systems.

I'm too much of a wimp, if someone asked me to supply CH antifreeze, I would not supply an automotive one as I don't think I would have much support when my neck is on the block.

This is my last post on this thread as I feel you ar looking for confirmation that a low cost automotive product will be OK in your heating system, and from what I know I could not support that view.

 

[joepar]

Thank you again.
I'm not looking for confirmation for what I want to do. So far, unfortunately, the reasons you gave me does not tell me why not. One of the manufacturers I wrote to with the same inquiry has this to say:

From: AMSOIL Technical Services Department

Thanks for taking the time to contact AMSOIL with your concerns.
In response to your inquiry, yes, AMSOIL Propylene Glycol Antifreeze/Coolant (ANF) may be used for this application. In fact, someone did some research on this a while back and determined that the product recommended by the heating plant manufacturer was actually propylene glycol.
~~~~~~~~~~~~~~~~~~~~~~~~~~~

I'm still awaiting responses from two other major manufacturers of AF.

The B737 rudder failure was simple due to lack of routine basic lubrication.

The parts of an internal combustion engine where the coolant has to travel is made of cast iron for the block, aluminum for the head (mostly), plastic in the heating system, copper or aluminum radiator and rubber.

I did read the backflow site you referred me, and it is important to note that their answer is a valve that sets a pressure differential to control backflow. I have such a pressure reducing valve at the inlet to the system reducing the street pressure from 75psi to 18-20psi. Our check valves are of high quality and not prone to failure. I've removed the two from the system and found them sound after testing them with 70psi air pressure.
These valves are as old as the system or about 14yrs.
I'm impressed about the life of the boilers made in the UK getting that much life out of them. Maybe, we should start importing them into this market. I'm going to ask around if those brands are available here.

This subject intrigues me because I think I may be into something no one has bothered to research or cared to look into, being used to what comes naturally and because of liability concerns.

Again, I thank you for your opinions and hope there are others who may be able to shed light into the issue.

 

[Archimedes]

Automotive coolant/anti-freeze mix is formulated for that purpose and that purpose alone. Cheaper coolant mix is usually based on ethylene-glycol which is highly toxic (therefore environmentally hostile) and not something that anyone in their right mind would want in a domestic heating system. In the UK, and most of the civilised World, it may only be disposed of at specified waste mangement/recycling sites and is illegal to dispose of it otherwise.

If you take a look at some of the enthusiasts' car or bike forums, using cheap ethylene-glycol anti-freeze is frequently cited as the cause of early waterpump failure and choked waterways. (BTW, I would argue that modern high-performance engines in motor cycles and cars contain many more dissimilar materials in their cooling and heating systems that those found ever found in a domestic system.) As an example, take a look at: this

For this reason, I and thousands of fellow riders, will only use Procool (an inhibited propylene glycol antifreeze/coolant mix) in Honda motorbikes even though this is significantly more expensive than 'cooking' anti-freeze that you buy in the supermarkets or Halfords. And, I'm not sure how often the H & V experts suggest you change coolant but in a car or a bike it is an annual or bi-annual job if you use EG coolant.

I can't see how the long-term risk is worth the few quid that you might save initially.

Just my £0.02 worth.

A.

 

[mave]

I'm listening Jeopar!
You said you aren't looking to save money, you're looking for a superior product. I'd appreciate hearing the results of your enquiries.

mave

 

[joepar]

I've found that the plumbing industry uses a Propylene Glycol base much the same material as required by Honda. This product is also sold for automtive use and it's reduced toxicity vis-a-vis Ethylene is the preferred feature. It is not anymore expensive than the Ethylene base but a lot cheaper than the plumbing industry product. The other additives to inhibit rust, corrosion and foam seem to be the same chemicals. I need to emphasize that my system is not combined with the hot water system. It is segregated from the main water source by a Watts Backflow Preventer equipped with Atmospheric Vent followed by a Pressure Control Valve that reduces the line pressure from 80psi down to 18-20psi. Since the system is 14 years old I decided to check these components for debris and function. The PCV was jammed by corrosion and not working properly which caused the lack of feed. I'm going to remove the Backflow valve and check this out as well. I believe that the best assurance is to make sure the protective devices are all in good operating order. So, even if I have to go through the effort of removing them, it is a comforting feeling to know for sure they all work.