Help needed with underfloor water heating

[Sho_86]

Hello everyone,

 

I have joined to ask for some help/advice.

I had a house built which was finished this January. The whole thing was a mess and I am just glad it got done somehow.

I am in no means expert in house building but some things I had to do myself which was good for experience however would have been better to know this beforehand.

I will make a separate TLDR post detailing what went wrong during the construction.

 

This topic now is to ask for help regarding our underfloor water heating.

The contractor who did the heating/ventilation and plumbing did everything but probably he didn't check the things when he was done and didn't do any fine tuning.

I am playing this game with him since the middle of September, where he promises to come the next week and never does.

 

We have a heat pump which supplies the hot water for the underfloor heating and the hot water for the building.

We moved in this January and the outside unit of the brand new heat pump broke after 4 days of use. Of course we had to wait a month for a new one and when it arrived it was too cold to put into operation so we did the winter with the heating element of the indoor unit of the pump.

In itself this already consumes an enormous amount of electricity but we had an ever bigger problem. The heating circuits never closed fully. Even when the thermostats are off there is still water from which I can clearly see in the distributor. This resulted in having 29 degrees inside.

I had to keep putting the heating pump into summer mode every other day and leave it until it got cold again. And of course all this with the heating element so we easily racked up a 4500 kWh consumption in 3 months.

 

Now after the outside unit got changed things did improve a little and this winter I turned on the heating a few weeks ago and now the temperature is at a 24-25 degrees, even though all the thermostats are only set to 21.

I wanted to do the hydraulic balancing on the flow meters since I know for a fact the guy who built it didn't do it himself. After the calculation and having printed out the tables to use for it I opened the distributor and then I noticed that some of the heating circuits again have water flow even though the the thermostats and actuator are off.

So please could anyone tell me why this could be happening? I am including a picture, this is from upstairs, from the 5 heating circuits only 2 are fully closed, the other 3 have water flowing through them constantly. This is just wasteful and literally defeats the purpose of having thermostats if the heating is always on anyway.

 

What I did so far is I unscrewed the actuator and the valve then closes fully, I can also completely push down the valve and it opens fully so there is nothing stuck there.

What I also did is I switched one actuator where there is water flowing with one where it is closed just to see what happens and everything stayed the same so its not the actuator that is defective. Also I would highly doubt that 3 would be immediately defective as they were brand new, plus on the ground floor NONE of them circuits are closed fully so that would mean 9 out of 11 brand new actuators are defective.

 

So if the valve itself isn't stuck, the actuator itself isn't broken then what else could it be?

Is there way to set the height of the valve, should have this also been done beforehand?

 

I have attached a picture, here it can be seen that from left to right only the second and fourth one have 0 l/h water flow. The other 3 all have considerable flow through them.

 

Thank you in advance

[ProDave]

More pictures please of any other plumbing stuff near the UFH manifold.

 

There is no sign of a pump or blending valve, so chances are it is circulating water far too hot through the UFH pipes.  And there should be a motorised valve or 2 to switch between hot water and heating.

 

As many pictures of all the plumbing bits please.  And there should be an electrical box near the manifold follow the wires from the actuators on the top and post a picture of that.

 

Initial assesment, the original installer didn't have a clue.  You are going to probably have a steep learning curve or find someone that does understand such things to sort it out.

[SimonD]

As @ProDave suggests, post a picture of the wiring centre with the cover off sowe can see the wiring. It's also worth checking the thermostats wired to the troublesome actuators to ensure they're not sending a live signal to the actuator when they shouldn't.

 

[JohnMo]

If I am correct in Germany, you have to be setup to run weather compensation.

 

If zones aren't shutting down its likely to be wiring issue. Or at least that's the first thing to check.

 

What's make, model of heat pump, and how is it controlled? 

 

You possibly need to split this into two sections, cylinder heating and house heating.

 

Not having a mixer and pump isn't an issue, flow temperature is, so this will need to be decreased.

[Alan Ambrose]

Well start with the simple stuff - I had one circuit that was always open because the actuator wasn’t clipped on properly. Easy fix. Next take off the errant actuators and observe whether they operate when the whole thing is switched on i.e. is the controller ‘telling’ the actuator to be on all the time. If you’re handy with a multimeter, you can also check the ‘signal’ from the wiring centre. (Note some actuators are 240V, some 24V.) If so, you have a wiring (or maybe a programming) fault. BTW you’ve shown good fault-finding technique so far, just keep up with the logical debug and you will either (a) find the fault or (b) prove good some of the components.