Calculating Inhibitor quantity.

[RobertG]

I am currently studying my level 2/3 in plumbing and heating systems and thought Id ask the professionals. Is there a solid formula for calculating how much inhibitor to use on a heating system within different sized properties?

 

[ShaunCorbs]

Normally 1l does about 10 rads (but normally says on bottle how many rads it treats)

Standard house I normally use two bottles (2L)

 

[robj20]

Can you actually put too much in, or is it best to just use 2 bottles for say a 3 bed house.

 

[ShaunCorbs]

Can you actually put too much in, or is it best to just use 2 bottles for say a 3 bed house.

No as long as you don't go over the top e.g. 5-8 bottles in a 10 rad system

Normally 1 to 2 bottles will do most domestic systems

 

[Chuck]

I am currently studying my level 2/3 in plumbing and heating systems and thought Id ask the professionals. Is there a solid formula for calculating how much inhibitor to use on a heating system within different sized properties?

If you're a pro, you should always read the datasheet for any product you use for the first time. Fernox F1, for example:

https://www.fernox.com/sites/default/files/product_datasheets/f1_protector_500ml_v.001_1.pdf

recommends a concentration of 0.5%. It comes in 500 ml bottles so one bottle treats 100 l of water. That's typical for a 3/4 bed house. If you want to be accurate you can measure the water content of the system when you drain it, with the aid of a bucket.

It doesn't have to be spot on but don't underdose. For large systems, e.g. commercial, use a test kit.

 

[Best]

If you want to penny pinch, but still be sure of adding enough inhibitor, - put a full 500l bottle in and then half of a bottle (total 750ml) for a small 3 - 4 bed house. That way 3 bottles will do 2 typical small houses.
Just be aware of any direct thermal stores (with a direct heating link), because the cylinder will have massive amount of what is heating system water