installing a relay for a second circulation pump on Daikin heatpump system

[tkalfaoglu]

Hi there.. I recently had a Daikin heat pump system installed for heating the house. (air to water, model EKHBRD016ACV1).

However the built-in circulation pump deemed insufficient for the 3-story house, so the installer added another circulation pump to the system.

The second pump is connected directly to 220v mains, and runs all the time which irks me to no end, thinking of the wasted electricity.

So I ordered a 220v relay in an attempt to take connections from the original (internal) circulation pump, and activate the relay, which will activate the external pump. This way, the external pump will only run when necessary. At least, this is my plan. Does anyone see a better way of achieving this, or why this might fry up the machine?

Many thanks, -turgut

PS: The forum will not let me post.. says something about banned keywords found??

 

[tkalfaoglu]

update: I removed a smiley and it then let me post.

 

[Ermintrude]

What's the current draw for the relay? If it's less than the pump gr8. Hasn't the unit got built in external relays you can set up in firmware settings ??

 

[tkalfaoglu]

Well, a relay has to draw less than a water pump, hence I thought I'd use it.

The heat pump is a complete black box to me. Electricity goes in, heat comes out. Therefore, I'm trying to be minimally intrusive to it. The local installer said it would be "impossible" to connect the second pump to it. I fail to see that, especially if I use a relay so that there is no big current draw from the machine.

 

[josh]

If the pump in the unit is insufficient, why not remove it and just have the bigger one wired in instead, in general if any pump is undersized/becomes undersized due to extension of the system you don't just shove another bigger pump in front of it and have both pumping one line.
Sounds like someone doesn't know what their doing and hasn't asked for Daikins advice.

 

[Jimbob]

Iv done this in the past! Just a switched relay off the original pump feed. The heat pump pumps are utter crap and often a smaller port to port size.

The 'recommended' solution us a low loss header, but takes space. A buffer would be best but not always visible

 

[Howsie]

Get the original installer back as this is what you've paid them for. If you mess with it you've given them a get out of jail card should anything go wrong in the future.

 

[Worcester]

Low loss header or buffer tank is the only solution, the Heat pump will cut out with all sorts of error codes if you try run another pump in series.

Your installer should have known this.

This way the buffer tank / LLh acts as the heat source and the 2nd pump runs when required to meet the heating demand / programme.

Did you have it done by an MCS certified installer so that you could qualify for the RHI payments and effectively get your heat pump for free?

 

[tkalfaoglu]

hi there. I do have a low loss header - yes when they installed a second pump, they did install that header thing. (It still baffles me how that thing works, but I watched animations on the net.)
Anyway, I just meant about the second pump running all the time.. Actually these days its a welcome thing as its getting pretty nippy here in Izmir Turkey. ( 3 degrees C this morning) and the heat pump seems to run all the time.