underfloor heating not working

[oinkment]

Unsure what to do with the under floor heating system.
It doesnt work. Its about 5 years old and ive just moved in to the property.

What things can stop the system from not working?

It is a water based system which has 3 valves going in and 3 return.

I recently had the boiler and radiator system flushed out with water and magna clean professional installed. Is it possible that sludge maybe in the underfloor system?

I was told it would not be possible to flush the under floor system as there is no external drainage. Does it need external drainage or would the 3 return pipes be ok?

 

[jackthom]

Does the pump run when the heating should be on and does the boiler at least fire up briefly? Some pictures of the system might get you the help you need.

 

[oinkment]

Yes the pump is circulating and does get very warm.

 

[oinkment]

manifold

• oinkment
• 25 Nov 2013
• 1

 

[Boilerman2]

Have you let the system run for long enough to heat the floors?? it can take several hours of operation before the floor reaches it's full temperature, as the floor acts like a huge storage heater

 

[oinkment]

manifold

• oinkment
• 25 Nov 2013
• 1

The red pipes are all warm from the top to the bottom.
1 of the 3 cold pipes is luke warm and the other 2 cold.

 

[thompo]

Could be the return valves are closed and system effectively off.

Try giving the blue valves a few turns in and out to and see if you get any movement on the black guages.

With the system on and pump running the black guages at the top should be registering a flow, if the top manifold is warm and the guages are showing flow, then you should have heat, as mentioned, give it a while to heat up.

 

[oinkment]

Could be the return valves are closed and system effectively off.

Try giving the blue valves a few turns in and out to and see if you get any movement on the black guages.

With the system on and pump running the black guages at the top should be registering a flow, if the top manifold is warm and the guages are showing flow, then you should have heat, as mentioned, give it a while to heat up.

Untitled

• oinkment
• 26 Nov 2013
• 1

The blue ones are just cap - I've taken the cap off...

 

[Diyisfun]

I had probs with mine when I moved in last year, it was a faulty motorized valve.
Changed the motor & now brilliant, as said mine takes 2hrs to warm up.
I have it set at 20 for 7.30, to go off at 6pm, after initial heat up I don't think it comes on again.

 

[oinkment]

Untitled

• oinkment
• 26 Nov 2013
• 1

There is some heat coming !

The screws on the red ones were down / turned off !

On the taps for the red ones it says L/min but I cant make out any readings. Is it supposed to change colour or something to say what the flow rate is?

 

[thompo]

Screw the blue caps down.

The pin sitting up on the one you have removed is the valve. When you screw the cap down it pushes the pin and opens the valve allowing flow. These should act like an on/off switch.

Top ones are the flow adjusters, used to balance the system, unscrewing increases the flow rate. Just dont unscrew them too far incase they come off!

There is normally a disc or something inside to indicate flow. On mine the disc is at the top when there is no flow. Then it moves down to indicate the flow rate.

 

[Diyisfun]

My system came from here
http://www.ukunderfloorheating.co.uk/
There is a link on there that shows how to commission, it may help you.

 

[Diyisfun]

Found it
http://www.ukunderfloorheating.co.uk/resources/fault_finding_and_commisioning/

 

[JayPage]

the blue caps are in place of actuators. Screwing them down fully will give you no flow through that zone. Take the blue caps completely off and check the return temp in 30 mins or so. You should also check that the TRV on the flow to the manifold is not turned down too low and that the IV on the return from the manifold is open.

 

[Agile]

The pin sitting up on the one you have removed is the valve. When you screw the cap down it pushes the pin and opens the valve allowing flow. These should act like an on/off switch.

That does not seem correct to me!

I would expect the valve to be open with the blue cap off!