Underfloor heating woes

[maillme]

Hello,

We have recently purchased a new house in Amsterdam - on a man-made island called Ijburg. It's unique and modern in a lot of ways, and one such way is the absence of gas to any properties - everything is done through "stads verwarming" - or city heating.

This basically means the power station (also on the island) pumps hot water to the property. This is then used for your hot water supply AND to heat the underfloor heating, which is installed in each home.

It is a closed circuit system, with water as the "fuel"

Now, the problem we have is that we put carpets and underlay upstairs and laminate downstairs - we followed all guidelines re: carpet etc... but, with only 1 thermo stat, it is causing a large temp difference. approx. 2.5 during day and 5 degs by the time morning comes around again. We are cold at night

The system has 2 manifolds - which appear identical.

On each manifold (after consulting with the company that installed the systems) - there are 2 thermostatic valves.... one controls the supply and one controls the return (water back out the property to the power station).

Also on each manifold is a small box which has an electrical supply and is attached to the pump on each manifold - according to the company that installed it, this is a device that cuts of electricity to the pump if the temp. gets above 60degs C - to protect the system / floor from over heating.

The problem I have, is that apparently the power company that controls the water to the properties, has regulations that do not permit the supply valve to go as high as 5 (it has dial 1-5) - I believe it is only 1-4 that is permitted. In our case, each valve is locked and will not allow us to get above 3.

My thinking was, I could turn the supply valve downstairs to 2, and upstairs to 4 - and then trial and error to get a balance.

With the mis-match in temperatures, there is what feels like a constant draft. But, It is looking likely, that with the carpet floor coverings, no matter how long the heating is on, I can not get above 20.5 degs upstairs - so I really need to try and get the supply turned up to 4 (but as I stated, this is locked) in the hope this can raise the temps. According to installation company, 1-5 represents the following:

1 23° C 2 34° C 3 45° C 4 56° C 5 67° C

The other option is to have a second thermostat fitted (there is, in effect 2 heating systems in the house) - but, the company wants EUR 1500 to make this a 2-thermostat (wireless) system - which is just waaaay to high.

I considered installing a google Nest - but installation company says this is not possible as it is a high voltage system - although, I'm not so sure it is.

I took the thermostat off the wall (as it detaches, in order to change batteries - you can see pic) and took upstairs with me, and it monitors the upstairs temperature as expected - as the sensor is on this unit - and, it appears to control the heating as it does when downstairs....

So, my questions(s) are:

1. Can anyone see from the pictures how the actual communication between the thermostat and heating system is taking place?
2. Do you think I can install a 2nd thermostat for less than their really high quoted price?
3. Does anyone know anything about this temp limiting device? There seems to be a small selector on each unit, with options 1,2,3 - downstairs is at 1, upstairs is at 2.
4. Any other suggestions? - we are very cold... and I'm not a heating let alone an underfloor heating expert
5. Temperatures in different rooms are almost a degree different - any idea's why? (all the flow vales are fully open) We placed thermometer in our sons room (which has 2 windows) and it was 1 degree colder than our own room..... the windows do not appear very draughty

I feel the company may be exploiting us a little bit, in the hope they get more money - the property is less than 6 years old.

thank you for any help....
Neil

supply valve

• maillme
• 30 Mar 2015
• 1

"Channel selector" - max temp regulator

• maillme
• 30 Mar 2015
• 1

Thermostat unit wiring (located downstairs)

• maillme
• 30 Mar 2015
• 1

Upstiars manifold

• maillme
• 30 Mar 2015
• 1

 

[Norcon]

Try increasing the valve setting on the left.

Are you sure the valve on the right is a return temperature limiter?
Try adjusting that valve to increase the return temperature.

Which should automatically increase the flow rate.

The return temperature limiter will slow down the response time on your floor heating.


Some systems with modulating valves can boost the flow temperature to increase the response time on heat up. And work very well.
If a return temperature limiter was fitted it would make that function virtually useless.

 

[maillme]

Hi Norcon,

thanks for your response.

To be honest, my knowledge is limited, so I contacted the company that installed the heating (as their details were given to me along with the CAD drawing of the pipework). I've pasted their emails below - but this is what has led me to think what I know.

The problem is, the valves are limited to 3 maximum.... but, from his email - I think they should be limited at 4.....

I can feel the heat in the floor, even upstairs (right now infact) - but it just doesn't bring the room up much.

Dear Neil,

Builders choose to use only one thermostat for both floors, with an option (extra work) for an extra thermostat so that each floor could be served by its own thermostat.
Only a few owners did choose the extra thermostat.

Afterwords we installed already many extra thermostats with wireless systems because the owners did not want the necessary drillwork for a wired system.

The thermostatic valves with numbers 1-5 represent the temperetures 1 23° C,
2 34° C,
3 45° C,
4 56° C,
5 67° C.

Normally the position is between 3 and 4.

The Nest control system is a low voltage system, all systems at Blok 17 are 230 V.
So you cannot use a Nest control system.

If we can have your address and the number during building construcion –to be found at drawing with floorheating f.i. Blok.. Bnr…..-
we gladly will make you an offer to provide you with a wireless system with thermostats for each floor.
Please state also your wishes floor by floor or room by room if you are interested.

and then after my response with more questions about the valves etc

Hi Neil,

Valve nr. 1 is the supply and volve 2 is to limit the return temperature.
Both valves are locked, due to regulations of “NUON Stadsverwarming”. (nr. 2 must be locked at 4 anyway)

The white/yellow box is a maximum temperature security box. It breaks the electric circuit of the circulationpump at > 60 degr. C. to protect your underfloor.

Sure you can try to balance out temperatures with both manifolds.
Empirical fact is that it is very hard to balance out with only one thermostat but, it is worthwhile to try.
To change the instalation into a system with two wireless thermostats (one for each floor) will cost you approx. € 1400,00 - € 1.500,00 incl. V.A.T.

 

[Norcon]

"Both valves are locked, due to regulations"

I'd be unlocking the return temperature limiter.

Also there's a special way to lay UFH pipes when a valve with that capability is fitted.

So its district heating.
How are you billed for this system?

 

[maillme]

I'd like to unlock it, but I can't see a way to do this - it looks like if I force it that it will break.....

How does this affect the temperature of the house though? Does this mean that it keeps the water in my system until the temperature drops to a low enough level, to be "sent back" the the supplier?

Yes, district heating. Its charged in GJ for the "heating" of the water..... the GJ price is set yearly by the government I believe - and every supplier who has such a system / offering must charge this amount.

2015 is set at EUR 22.64 per GJ. Quite what this means I have no idea yet, but at this rate i'll have the dearest bill in Ijburg! lol

Neil

 

[maillme]

Here is the pipe-layout:

Pipe layout

• maillme
• 31 Mar 2015
• 1

 

[Norcon]

"Does this mean that it keeps the water in my system until the temperature drops to a low enough level, to be "sent back" the the supplier? "

Yes.
It's a flow restrictor based on temperature.

 

[maillme]

So, this water could be too low to heat my house any longer but too high for the supplier to want it.... right?

Why would they want to restrict this?

Neil

 

[Norcon]

Yes wrong pipe layouts.
When you control the return temp then double meander as used by Rehau are essential.
As it balances the floor temperature much more evenly.

 

[Norcon]

"Why would they want to restrict this?"

It might have something to do with how you are being billed.

 

[maillme]

Hmm, they install a big box which is sealed with huge cable ties - so i've never seen inside it, but it's a kind of polystrene effort (see pic).

There is then a meter coming out of this - it was my understanding that the billing is done as the water enters the property.....

I'm not sure I understand about the pipe layouts - so they should be laid a different way? It wouldn't surprise me if they did it the wrong, easiest way - most things in Holland seem to be the easiest way and not necessarily the best way.....

I just did another test, by putting a thermometer in the bathroom (which does of course not have the carpet) and it is 2.5 degrees warmer than our sons bedroom - 1.5 degrees warmer than our bedroom... so the carpet makes a huge difference - but the problem seems to be that the system can not be changed to cope with the carpet - e.g. I can not increase the temp of the system....

So even if I were stupid enough to take the offer from the company of a 1500 second-thermostat system, it would make no difference to the current problem....

Flow meter

• maillme
• 31 Mar 2015
• 1

Meter

• maillme
• 31 Mar 2015
• 1

 

[Tipper]

If you can find a manufacturer's name(s) on the thermostatic valves you should be able to find setting and locking information on the internet.

Sometimes they have a clamp screw to prevent fiddling and sometimes a locking collar that pushes into the rear of the knob.

 

[maillme]

unfortunatelly I inherited the heating with the house, i didnt have a choice(other than choice of house )

 

[Norcon]

You could try removing the sensor phial and cleaning off any heat transfer paste that's applied. Might be none though.

Then try lapping a few wounds of pvc tape around it and place it back in the pocket.
That should cause the injection valve to throttle open and increase the flow temp.

You'd need sensitive temperature measuring devices ideally to see the exact changes.
I don't think the rtl will have a phial.

 

[maillme]

Hi All,

Thanks for your replies.

So, an update.

I managed to get the caps off the thermos valve (actually, it looks like it has been done before...) and was able to turn it up - but, this didn't really have any affect. Infact, I'm beginning to think of something else is faulty.

The pump appears to be operating - but, I'm basing that on the fact that I can hear it / feel it - however, the whole system now (upstairs) - even although the heating is on, is stone cold - downstairs is not - it is really warm to the touch (manifold etc).

Even the supply pipe, which comes from downstairs, up to the thermos valve is cold..... does this point maybe to the yellow/white box which is supposed to be regulating temp?