UFH - Do I have an air lock?

[Doobrey]

Guys,

Firstly, you are so very helpful, so a big thank you.

I am trying to figure out the final bits of my UFH puzzle and would appreciate some final advice.

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• Doobrey
• 20 Nov 2009
• 2

This is my UFH manifold. The bottom copper pipe comes from the boiler, through the main pump, into a motorised valve, then onto a thermostatic valve and then into the UFH pump. The water arrives at the copper pipes under my stairs. Following this pipe (and measuring the temperature) it arrives around 35 degrees. At the U-bend at the bottom of the copper pipe, as it turns horizontal and enters the manifold it drops down to 25 degrees. Is this normal, or is there perhaps an air lock?

If there is an airlock, how would I fix it in this system please?

With thanks,

Doobs.

(Airing cupboard picture)

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• Doobrey
• 15 Mar 2012
• 1

(Full picture of manifold)

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• Doobrey
• 20 Nov 2009
• 5

 

[Boilerman2]

Have you tried adjusting the TMV, it should allow water to flow at about 40'c, can you post a pic of the TMV?

 

[Norcon]

can you post a pic of the TMV

He already has.
Which looks like an ESBE.

 

[Doobrey]

Yes esbe. It's currently set to 3 of 6 clicks.

The main issue is that the copper pipe coming vertically down loses the 10 degrees in temp...

Doobs.

 

[simond]

Is the UFH working?

Why are you measuring the pipe temperature?

If you are not happy with the floor temp have you tried adjusting the mixing valve?

 

[Doobrey]

Hi Simon,

Thanks for the reply. The UFH in the front room gets warm, but no where near how we would like it.

The Kitchen is really warm, as is the utility room.

I "know" there is a faulty lockshield valve, which I am going to replace. There is something weird going on, for example, if I shut off all of the lockshield valves except the living room, then the outbound pipe (measured with a laser heat device) shows 50 degrees. My understanding is that this is the max that we can use for a screed covered floor. The return pipe is 30 degrees at the most... the pipe length is crica 80metres in length.

I have spoken to the guys that installed it, and they agree that it doesn't sound right.

A couple of other things to note. Under instruction, I attached the hose and cleared out the living room loop. Black horrible stuff came out the other end, so I continued to clear it until clear water flowed. I am wondering if I have put an air lock in there?

If I have followed all of the instructions about clearing an air lock on the manifold side - IE. attaching hose to input, attaching bucket to output, open one zone at a time and clear them, then the next, etc.. The finally open them all and ensure good flow. I am therefore thinking the pipe from the boiler, to the motorise valve, to the thermomixer, to UFH pump then down to the manifold "might" have an air block?

I have checked the UFH pump, by removing the big screen on the front, water dribbled out slowly, so I assume that is working ok, although it gets incredibly hot.

Any other advice?

Thanks!

Doobs

 

[Norcon]

Ideally you shouldn't be touching the lockshield valves if they were set upon commissioning and the system balanced.
Thats all probably coc a hoop now and the commissioners work wasted!
To turn off a loop adjust the wheel head valve.
Also manifolds with flow meters are a much better option.

Is the ufh circulator operating?
Did you try removing the slotted screw and turning the pump shaft manually to ensure it isn't seized with a screwdriver?
You put the screwdriver in through the hole inside the pump casing and locate the slot in the shaft.
It should turn freely.
Or remove the ufh pump and energise it and look into the outlet port and see if the impellar is turning.

 

[Doobrey]

Thanks, i'll give your suggestions a try...!

One other thing, do you always have to pressurise the system, even when you have "topped" it up due to replacing a valve?

As I have replaced a valve previously, but not re-pressurised....

 

[Doobrey]

Ideally you shouldn't be touching the lockshield valves if they were set upon commissioning and the system balanced.
Thats all probably coc a hoop now and the commissioners work wasted!
To turn off a loop adjust the wheel head valve.
Also manifolds with flow meters are a much better option.

Is the ufh circulator operating?
Did you try removing the slotted screw and turning the pump shaft manually to ensure it isn't seized with a screwdriver?
Or remove the ufh pump and energise it and look into the outlet port and see if the impellar is turning.

Is it easy to replace all the manifolds? They are over 8 years old now?

 

[Norcon]

Yes the system should be repressurised.
And no need to replace the manifolds.

As I have replaced a valve previously

If you have opened the system its probably full of air now as well.
Loops might need purging with mains pressure.

 

[Doobrey]

Thanks.

So my plan - replace the lockshield valve, which I know to be faulty.

Using the mains pressure purge any air from the system.

Then repressurise the entire system. Ok, throwing this out there, how do I know what pressure to re-pressurise the system too?

Doobs