White foamy stuff

livingthedream

Hi,

I have been having an issue with a radiator not heating up so a couple of weekends ago I decided to do some investigation.

Let's say this is the radiator:

Bleed nipple
^

---

|...................................... O Valve C
| ......................................|
| ......................................|
| ......................................|
| ......................................|
| ......................................|
| ......................................|
| ......................................|
O ValveA _________________O Valve B

I have tried bleeding the radiator and there appears to be no air trapped in it.

So on saturday I did some investigation to try and see what the flow through the radiator was like.

I removed the cover from valve C and ran a hose from it out to my garden connected to a pump providing suction.

Scenario 1:
With Valve A closed I opened Valve B and turned on the tap in attic to top up the system. Net result was a good flow of water out of the hose.

Scenario 2:
Closed valve B, opened valve A. Result was a slow flow of white frothy stuff out of the hose (see pic). I have no idea what this stuff is. It appears to be odourless. I thought it might disappear with time but I left it running in this configuation for 45mins and it showed no sign of reducing.

Scenario3:
In case the cause of this weird white stuff was something to do with the radiator itself, I removed the radiator and connected the hose directly to Valve A. The result was the same as Scenario 2.

Does anybody have any idea what the white frothy stuff is and why I am seeing it??

Cheers,

~LTD.

PK27

If a rad isn't heating it's not a problem with the rad, all that is unnecessary. A rad is not really functional, hot water simply passes through it and the rad releases the heat. If a rad isn't heating, the system needs to be balanced. Water takes the path of least resistance, and generally the water heads straight for the coil in the hot water tank. This is because the coil is 3/4" pipe the whole way through, and is the only part of the system that is, so it's the path of least resistance. Somewhere around the coil on the hot tank you'll find a valve for balancing.
Basically If it's open all the way the water has a free run. If it's closed you'll get no hot water. Close it fully and then open it about a quarter of the way. This makes resistance on the coil and pushes more heating water to the rads.
Next, you need to identify the flows and returns on all the rads in the house. A bit of red tape or red marker is a good way to mark them. Turn on heating and feel the pipes into the rads. One will heat quickly while the other remains cold. The one that heats quick is the flow.
On every rad in the house this should be fully open.
Next, identify which rads are heating fast. On these, you need to turn down the returns, (the pipe which wasn't heating fast). These rads are getting a better flow and are robbing the cold rads of water. So you need to close down the returns to stem the flow so that it gets sent to the cold rads. Turn them closed and then open them two turns. On the rads that aren't heating as well, and the one with no heat, have the flow and return all the way open. These rads need no resistance so the water is pushed through them easier.
Run heating for a good half hour.
If all rads are piping, you're done.
If any are still cold, go around the other rads and hold the palm of your hand on the face of the rad at the top. If you can't hold your hand comfortably on it for 7 seconds, turn down the return (cold side) another quarter turn.
Continue to turn down hottest rads until all rads are heating equally.
If that doesn't work get a new heating system !

livingthedream

Hi,

First of all, thank you for taking the time to write such a detailed reply!

My system at home has an elctronic valve to switch between heating water, heating radiators and doing both.

During all my testing I was only looking at the heating radiators bit.

I believe I tried something similar to your process previously, though possibly not as exact. I will give it another go...

Still stumped as to what that white foamy stuff is though!
Anyone???

Thanks again PK27..

~LTD

PK27

No problem.
The pic won't load but it's most likely an additive that someone put in along the way, most likely inhibitor.
It basically stops the insides of the system rusting and keeps the water cleaner for better running. Changes the viscosity of the water to flow better too.