The Best Hose for a Manometer for Boilers and HVACR
Nov 12, 2025
A manometer is an essential tool when working around boilers and HVAC equipment. It is used to measure items like gas and air pressure. You need to connect the manometer to the pressure port in order to make the measurement. Most manometers will come with some short length of hose, but is usually less than desirable material and length.
After a lot of testing and research, I found what hose works best for use with a manometer. There are two main differences when ordering hoses other than the material which is durometer and ID/OD.
Durometer
Durometer is a standard way to measure the hardness of rubber. Scale is from 0-100. 100 is hard, 0 is soft. 70A Durometer is still flexible, but is stiff enough not to easily kink and is firm in the hand when attaching to barbed fittings. This makes it easier to push/pull the tubing off of connections. This is the recommended durometer. 50A Durometer is more flexible than 70A, but kinks easier and stretches more as it is attached to barbed fittings. This makes for a softer connection when attaching to barbed fittings which sometimes can be a hassle. Having to make sure this tubing is properly supported so it doesn’t kink is the reason it is not recommended.
Tubing ID and OD
Having different ID tubing will increase the amount of proper connections on to pressure ports. The OD of the tubing can increase as there are different wall thicknesses. A thicker wall tubing has a larger bend radius (resists kinking), but cost more than thinner wall tubing. 1/16" wall thickness is the sweet spot between durability and cost.
Recommended Tubing
- McMaster-Carr 75236K6 ID-1/4", OD-3/8", Durometer 70A, Color- Red
- McMaster-Carr 51135K171 ID-3/16", OD-3/8", Durometer 70A, Color- Blue
Both models of tubing are the same material, but are different ID and color. I would recommend getting two different ID of tubing based on your needs. I found that 1/4" and 3/16" worked best over a variety of applications in the boiler industry. If you get different color tubing for different inside diameters (ID) you can easily pick out the tubing you need based on color instead of having to find an end to look at what size the tubing is. Also if you get red and blue tubing, it stands out more in darker spaces than black tubing so you don't leave some accidentally connected or on the floor.
What Makes This Tubing Good?
- Resist kinking- Kinks in the tubing will lead to frustration when you are trying to measure pressure and not getting a good reading only to find out your tubing is kinked.
- Heat resistant up to 390 F- Working around steam systems and boilers, there are many hot surfaces. Lots of cheaper tubing will harden and crack when exposed to higher temps.
- Durable- Tubing can be stretched and bent, but still holds its structure when you are connecting it to a pressure port.
- Not Sticky- You don't want a tubing material that is sticky and attracts dirt.
- Flexible when cold- Few things are worse when you are trying to connect tubing and the material is harder when it is cold and doesn't want to work with you.
Best Place to Buy
Unless you want to buy a 1000 foot roll of tubing straight from the manufacturer, McMaster-Carr has the best pricing and you can order different lengths of tubing. I would recommend you cut the tubing up into workable lengths like 6 FT and if you need longer, you can use a barb connector to connect two pieces of tubing together. You do what works for you.
If you aren't sure that this tubing is the best for you, order a few short lengths and try it out. I tried over 30 different materials of tubing to find this one and used it for years in the field and it never let me down. If you think you have a better tubing that works better than what I recommend or you bought the tubing and love it, please email [email protected] and let me know about it. Always want to hear what you have to say.
