Ground Source Heat Pumps

Fort_2

Was looking at Manuals and closest to mine would be combi unmixed heating circuit.  Fig 12 on worcester greenstore.
i said to installers that it should have been the one as fig11, unmixed circuit with buffer tanks .
as they have fitted room sensors in the bedrooms with temperature controls that are connected to manifolds but all those controls not connected to boiler.  So if i have 22c on ground floor in winter then 1st floor is 18c, i want to have heating in the bedroom, roomstat only opens Actuator on manifold but heating is not starting as roomstats Are not connect to boiler. And temperature downstairs is high, witch is one big loop.
 They have even ran a cable for that into boiler but is just left loose hanging near boiler.

So i am trying to make it work a bit better.

beardymarrow

Fort_2 said:

If do something like that, would that be better, you think?
i will be replacing that valve, could move pipes a bit at the same time. 

Yes, that looks better. I wouldn't worry too much about it though until you've got the 3-way replaced and seen how it functions. It's tweaking for efficiency rather than a big problem.

Fort_2

hi, what bypass valve is fitted on yours? 

Mine is manual and fully open, do you think automatic would be better? 

beardymarrow

Fort_2 said:

hi, what bypass valve is fitted on yours? 

Mine is manual and fully open, do you think automatic would be better? 

Mine is just a manual one (basically a tap). Automatic would be better, but as long as the manual one is set right, it's fine. It shouldn't be fully open though (are you sure it's fully open, not fully closed?), otherwise you'll get flow over that in preference to the rads. You should only get flow across the bypass only when all the rad valves are closed, so it needs to offer a higher pressure (more restricted) route than the rads. Is it hot after the valve when the heating is on, even if the rads are on? That would mean theer is flow across it and it's turned on too much.
To set it, turn the GSHP off and let it cool completely. Close the bypass valve. Close all the rad valves. Turn the heating on, and gradually open the bypass until the pipe coming out of gets hot. Then stop.

Fort_2

It is a lever valve and it is in fully open position. I did not do any adjustments to it, thats how it was all time. 

thats why i thought automatic would be better as you can set the min flow required for boiler.

I think this could be the reason for lower temperature upstairs during winter. 

It could be pushing some of the heating back into boiler. 
What other valves do you men when say all red ones? 

As i dont have any other valves on heating side. 

The only other valves would be on manifolds for underfloor heating. 

And one on return pipe with filter in it. 

beardymarrow

Fort_2 said:

It is a lever valve and it is in fully open position. I did not do any adjustments to it, thats how it was all time. 

thats why i thought automatic would be better as you can set the min flow required for boiler.

I think this could be the reason for lower temperature upstairs during winter. 

It could be pushing some of the heating back into boiler. 
What other valves do you men when say all red ones? 

As i dont have any other valves on heating side. 

The only other valves would be on manifolds for underfloor heating. 

And one on return pipe with filter in it. 

Is it definitely fully open (does the pipe get hot on the return side of that)? That's not right if it is, unless there's some sort of restriction to flow (which will generate pressure), then the bypass will get used in preference to the rads/UFH (especially upstairs ones) as it'll be an easier route for the water than going all the way upstairs, and like you say the flow will just go straight back to the boiler.
When I talk about the rad valves, I mean to turn off the thermostatic valves on each of the radiators. If it's UFH, then turn off all of those. If you've UFH loops or radiators that don't have thermostatic valves on them, then I don't know why you'd have a bypass anyway, as it's pointless. The bypass is intended to provide the boiler with a route to flow the water in the situation that all of the thermostatic valves on the radiators and UFH zones are closed.

Fort_2

It is under floor heating, ground floor only has manifold and loops are adjust manually and upstairs actuators from bedroom roomstats. 

There is a towel rail in the bathroom that Has valves open all the time. 

Thats why i am thinking automatic valve with minimum setting required for boiler, just in case, would be better.  

When i was reading manual for installation on Bosch unit thats set up is like mine or similar it said:

Fig.12 Unmixedandmixedheatingcircuit

An absolute prerequisite for the connection is that a minimum flow of at least 70% of the heating system volume can be maintained throughout the year.

* If a bypass is used and an external circulation pump is fitted, the flow over the heating system can be reduced by 40% of the heating system volume of the heat pump. Ensure that most of the thermostat valves are fully open.

Fort_2

Just got home, and checked it.
it was fully open and bypass is hot and pipe that is going back into boiler is hot as well.  Pipe going away from bypass valve, towards manifold is cooler, slightly warm to touch. 

Just thinking as why heating pipe coming out of boiler would be hot, as i dont have heating on. Shouldn't the pipe be cool as no heating needed? Or could this be due to faulty 3port valve? 

Fort_2

Left it 1/4 opened and when hot water starts heating, pipes going to wards manifolds and manifolds got hot. 

House being heated when hot water is being produced. 

I probably should leave it open for now until i replace that valve as i will have heating on. 

beardymarrow

Fort_2 said:

Left it 1/4 opened and when hot water starts heating, pipes going to wards manifolds and manifolds got hot. 

House being heated when hot water is being produced. 

I probably should leave it open for now until i replace that valve as i will have heating on. 

Yeah, I bet it's hot because of the 3-way. Get that replaced and then let's revisit it. I think you'll still want to close the bypass a bit to stop it being used in preference to the upstairs (depending on what you're doing with external pumps), but we'll be able to tell that once the 3-way is working properly and you're not sending your domestic hot water around your radiators anymore :-) Don't worry it's not actually the hot water that will go round the rads, as there's a heat exchanger, so you won't get rusty radiator water out of your taps :-)