air source heat pump installation

[harry22]

Hi, I have just acquired a new air source heat pump to replace the old one which died a couple of years ago.

On the old one, there was a connection from the heat pump to the central heating circulation pump. On this new one there is no additional wire provided for this. Added to that the heat pump came with a separate circulation pump. I am wondering if the heat pump has an inbuilt circulation pump and this additional pump is for use with a secondary coil in the hot water cylinder.

The heat pump was sold to me new by someone who decided to try importing them but has given up on this. It sat around in a warehouse for several months, been opened up to have a look at and sold on to me.

The heat pump has two holes in the case for wiring to enter, one which has the main power cable and a second which has the controller and heat sensor. There does not seem to be enough room to feed an extra wire in through the casing, unlike my old heat pump which came with a second wire for connection to the circulating pump. On the circuit diagram there is a connection for the

One other question is that my grunfos pump has not been touched for a couple of years but has had water in it for the whole time. Should I be worried about it working

This is the manual for the installation

http://www.sundezheatpumps.com/Manual_Sundez air-water heat pump for house heating(LED) 2011.pdf

any help would be greatly appreciated

Thanks

 

[on31ll]

Hi it does seem that maybe your a little out your depth here ? Maybe im wrong. Would it not be easier to call in a pro and it could be a quick fix ? And he will advise you on other issues (pump etc)

guess its just down to how handy you are an how you value your time.

 

[snowhead]

The drawings show connections for 2 or 3 external pumps depending on model and a layout including pump locations.

 

[harry22]

thanks snowhead. It is a simple heating system with 6 rads and one grunfos circulating pump.

The thing that is confusing me is the lack of space in the holes to feed a power supply into the unit and that the last heat pump came with a wire to connect to the circulating pump but no pump which is what I would expect. This ones comes with a pump but no connecting wire and limited space to feed it through the casing.

The wire on the original pump is chunky and thought to reuse that but maybe I just need a small wire for this.

Any further advice would be great

 

[Gray0689]

Let me get this straight are you trying to connect a air source heat pump directly in to your heating
No buffer tank or hydraulic tower???

 

[harry22]

yes, it is not the optimum solution but it worked fine with last heat pump

 

[Gray0689]

What do you have in underfloor or rads How much was your electric bill!

 

[harry22]

have a woodburner, highly insulated small house and oversized rads

any help with problem would be great

 

[harry22]

[FONT=Verdana, Arial, Helvetica, sans-serif]10. Do I need a buffer tank?
The manufacturers do not always agree on this point, but it is suggested that you go with their specific recommendations. A buffer tank is simply a quantity of water that can help to reduce the number of times the heat-pump has to 'cycle' (i.e. times it has to stop and start). It is particularly necessary in a larger property where many heating zones are involved. In well-insulated and open-plan houses a buffer tank may not be needed. In these cases, the floor itself can act as the buffer. However, the floor must have sufficient pipe in it with good thermal contact within a thick screed. High water-content radiators can act as a buffer.[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]The relative size of the heat pump also has a bearing here; if the heat pump is relatively large, it is more likely to need a buffer cylinder than a continuously-running small one. Furthermore, many air source systems now have variable 'inverter' motors. These 'modulate' their output, so rarely need a buffer cylinder. This is in contrast to fixed-speed air source where the heat output will vary greatly depending on the air temperature outside, so buffers are often recommended here.[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]In summary; having a buffer tank is playing-safe, and recommended if the radiator or underfloor system is unknown, or un-matched. With well-designed house and well-designed emitter circuits, you might be better off without one.[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]
[/FONT]

 

[DirksPlumbing]

10. Do I need a buffer tank?
In well-insulated and open-plan houses a buffer tank may not be needed. In these cases, the floor itself can act as the buffer. However, the floor must have sufficient pipe in it with good thermal contact within a thick screed. High water-content radiators can act as a buffer.

I think you gave the answer away yourself? High water content and large on radiators means you will have spent pretty much as much as for a proper UFH. Have you?

 

[harry22]

I think you gave the answer away yourself? High water content and large on radiators means you will have spent pretty much as much as for a proper UFH. Have you?

Did not do UFH because the ground floor of the house is 50% solid concrete uninsulated floor and £50% timber suspended floor. On top of that is a solid maple floor. Redoing the floor for UFH would mean cost of removing the floor digging down, hardcore, blinding, insulating, concreting slab, screed and new maple floor which would me many thousands, so left it alone!


Back to the original question is should I be connecting the existing grunfos circulating pump to the heat pump board?

 

[ecowarm]

If you read the instruction manual you will find the answers, but also it will tell you " the installation should only be carried out by qualified personnel with adequate knowledge and experience"

 

[Gray0689]

Ps if your floor has no insulation it can't be classed as highly insulated
No point doing half a job