Filling central heating after fitting new radiator.

[wullie]

After fitting new radiator , what water do i use, been told deionised but want to check.

[Tonka]

Wet water or dehydrated 

[dor]

Water mixed with at least 33% antifreeze/corrosion inhibitor.

Mix in first, otherwise you risk density stratification in the radiators which can stop the water circulating within the rad (which relies on the density difference between the hot and cooler water, i.e. not very much).

ETA: don't worry about deionised.

Edited August 7, 2017 by dor

[koukouvagia]

4 hours ago, Tonka said:

Wet water or dehydrated 

Yep, this is what you need. 

[AllanC]

That's a bit misleading as you really need to read the instruction on the side of the can. One can of Dehydrated water mixed with one gallon of water produces 10 gallons. A lorry carrying the raw product to the cannery crashed and overturned in the rain a few years back. It caused a major flood in a local village.

[cuthound]

7 hours ago, dor said:

Water mixed with at least 33% antifreeze/corrosion inhibitor.

Mix in first, otherwise you risk density stratification in the radiators which can stop the water circulating within the rad (which relies on the density difference between the hot and cooler water, i.e. not very much).

ETA: don't worry about deionised.

I filled my Webasto CH system with 50% antifreeze/water mix and found that the radiators wouldn't get hot until I had (on the advice of NMEA of this parish) reduced the antifreeze strength to 25%.

I agree that it is not necessary to use deionised water, unless you are frequently draining and refilling the system, cos the scale only drops out of water once.

[Taslim]

As ^^^ To much antifreeze isn't good.  Right royal game draining down to re fill too.

If you must use dehydrated water be sure to read the directions on the tin.

Edited August 7, 2017 by Taslim
fat finger