how do I add an inhibitor to a sealed pressurised system

[johndriscoll]

Have just installed 2 towel rads and 7 TRVs. How do I add an inhibitor to a sealed pressurised system ie no header tank to pour anything in to. I also need to balance the system as some rads are just not getting hot. Are the infra red themometers Ive seen advertised any good. anyone recommend one cheap?

 

[mickyg]

easiest way if you have a standard filling loop just use Fernox F1 Express.
Dont waste time with a infra red thermometer. Been using my hand to great success for many years.

 

[bookahandyman]

bit of a hassle but drain down your system again , until one of your towel rads is empty, if upstairs you only need drain it down to that level.then undo blank off top or bleed valve nut. pour in inhibitor , refill system. alt you can isolate the towel rad by shutting off valves, then drain the towel rad on its own. or you can by the fernox express f1 inhibitor which you can inject throughthe filling loop.

 

[seco services]

. How do I add an inhibitor to a sealed pressurised system

pour it in one of the new rads before filling system.

Are the infra red themometers Ive seen advertised any good. anyone recommend one cheap?

yes they are good
i use a fluke one but they are quite dear for a one off use.

 

[boilerdoktor]

assuming you drained the system to fit new towel rails there must be a good drain off point!

drain off and open the whole bleed valve nut on the towel rail. after you have lost enough water shut the drain off. use a funnel and small piece of hosepipe and simply pour into rad. towel rails are heaven sent for this.

If it is an old system and sludgy you could do worse than put some sludge remover in to work its magic, drain again and fill with inhibitor.

I have no knowledge of those trv contraptions you talk of!

 

[MJN]

Are the infra red themometers Ive seen advertised any good.

That depends on which you've seen!

anyone recommend one cheap?

I can highly recommend the ETI TN1:

http://thermometer.co.uk/519-tn1-infrared-thermometer.html

Available for around £15 on Amazon. It has an accuracy of ±2°C - pretty much the industry standard for the sub-hundreds price point. The only drawback when compared to devices ten times its price is that it has a target ratio of 1:1 hence i.e. at 5cm away its target is 5cm across. You therefore need to hold it close to the object you are measuring.

Very handy for balancing radiators if - the instant readings almost makes the task something of a joy! Put a piece of insulation tape on the rad valves/pipes in order to provide a common representative surface to read off as IR thermometers do not function well on metal surfaces.

Mathew

 

[johndriscoll]

thanks for the info people, the infra red item looks OK. At the moment nearly half my rads are not heating up hardly at all. Before I start the balancing what should the boiler stat and pump settings be. Also how do I tell if a rad is unbalanced or maybe blocked. I did not install this system so I dont know the order of the rads from the pump and running around to check the order in which they heat up could be a bit tricky if some are not heating up at all due to another problem

 

[MJN]

At the moment nearly half my rads are not heating up hardly at all.

That does point towards a balancing or blockage issue (assuming they've all been bled).

Before I start the balancing what should the boiler stat and pump settings be.

Just leave them be for the time being, but do make sure your room stat (if fitted) is turned right up as you ideal want the boiler running continuously (to make fair comparisons between the measured rad temps).

Also how do I tell if a rad is unbalanced or maybe blocked.

If you turn all the other rads off see if the rad gets hot. Hot = balancing issue, not hot = blockage.

I did not install this system so I dont know the order of the rads from the pump and running around to check the order in which they heat up could be a bit tricky if some are not heating up at all due to another problem

Knowing the order doesn't matter - the iterative balancing process will reveal it and will sort itself out. As you throttle the hotter rads with the lowest drops the cooler rads will get a greater share of the flow. It's all in the figures - work systematically and you'll get there. Patience and optimism are key!

Mathew