Inherited UFH how to set up?

[CaptainOgre]

Hello, I have inherited a UFH system (~6 years old) which is present in a small grannie annex, the previous owner have left no documentation or instructions (so no idea on the pipe lengths) and it does not seem to be working very well, it still heats and flows but looking at the system and trying to understand it, it seems to be set up incorrectly, any help welcome!

1/ Pump - What setting should it be on . I, II or III and Constant, P-V diff or P-C diff

2/ What Flow rate should the three zone be set at? Rough idea would be helpful, they all drop to the bottom when the zone calls for Heat/flow

3/ What is this for?

4/ IS this set correctly?

5/Whole system image

6/ The thermostat (heatmister slimline v3/v2 are wired differently), picture two looks correct from what I can tell but any reason for the difference?

[ProDave]

Start by assuming it is working properly, and describe the problem you are having with it?

 

Is is just that you have never had UFH before, and you expect it to work like radiators, to come on, to quickly feel warm, and to quickly heat the room?

 

Of more interest is what user controls do you have, a time clock or programmer of some sort?  A wall mounted thermostat of some sort?

[sgt_woulds]

Also, what is the floor area in m2?

[sgt_woulds]

Judging by the flow meters, only the centre loop is working, but that may be because you have multiple zones and that is the only one calling for heat. 

 

However, seeing a flow meter maxed out like that is not usual and would indicate a zone about the same size at Trumps new ballroom...

[CaptainOgre]

Hi All,

 

Thanks for the comments

 

The system works in a basic fashion, but having done some research into UFH I'm confused as to how to set it up to run most effciently (heating and cost). I can get each zone to call for heat.

Zone 1, bedroom (6m2), Zone 2 batchroom (3m2), Zone 3 (9m2, (12m2-3m2)) 

 

Currently it take arounf 12 hours to heat the space from 15C to 20C and the things i'm concered about are;

 

Pump flow is set to max, none of the zone are balanced and all run at over 5l/m if they get activated alone and 3l/m if all zone call for heat at the same time.

I know how to set the flow by turning the flow meters but dont know what flow to set them, or what setting to have the pump on speed and contnast or PV or PC?

 

The return temprature is only a couple of degrees lower than the outlet tempature. 

 

What does the red dial do, I have no idea nad can seem to find a refernce so am leaving it along?

 

Which is the correct wiring for the thermostat? they are hardwired back to the Heamister UH4

 

 

 

[ProDave]

Does it run from it's own boiler?  or does it share the output of the house boiler?

 

UFH does take a long time to heat up.  It is best run to be on most of the day, some run it all the time.  

 

To set the flow rates can be a long process, run it for a long time with all the room thermostats turned up high, the rooms that get too hot, turn their flow rate down, the rooms that are cold, turn their flow rates up. You are aiming to get all rooms to heat up at the same time.

 

 

The red knob at the bottom is an automatic bypass valve, you don't need to do anything with that.

 

The black knob below the pump is the mixing valve and sets the water temperature in the UFH loops  The little guage top left of the manifold is showing the water temperature, looks to be about 40 degrees, I would not go any higher.

[John Carroll]

Would suggest running the pump in CP (constant pressure) mode (second pictogram down) on setting II which at ~ 4.2M head should be ample for your flowrate requirements, suggest setting the flowmeters to 2/2.5LPM, if you have temperature gauges on the manifolds note the readings and compare them with the present readings.

[Nickfromwales]

What are the UFH pipes sat in? Screed or in aluminium plates, or an overlay system? 
 

Any clues?

 

Defo down a notch on the pump, and go from there. 
 

With that long a time for it to heat up it sounds like possibly screed over concrete as that’s taking a bloody long time to get there!

 

>6hrs would bother most, and feeling the heat within 4 should be the norm.