What dial does what on my Heat Interface Unit?

[Matt95959]

Hi there, I'm new to the forum so apologies for any informalities.

My HIU in my flat is receiving hot water from the communal boiler but it's not fully distributing the hot water around the central heating nor hot water taps.

In the attached image there are three adjustable thermostats. Any idea on what regulates what?

Many thanks.

Matt

 

[ShaunCorbs]

Is it a rented place if so put it back to the maintenance team / landlord

 

[Matt95959]

Hi Shaun, I own the flat so One Housing a Group who manage the building aren't interested in helping.

 

[ShaunCorbs]

Tbh if it's been working fine it won't be as simple as upping a few stats, could be a few things

Do you know when the hiu was last serviced ?

Also anyone else having the same problems in the block

 

[Matt95959]

It was last serviced March 2016 so it's nearly due its next service. Anything I can adjust in the short that might help?

 

[ShaunCorbs]

You can try turning the green one up a bit from 2.5 to 3 etc

 

[johnf]

Is the circulating pump running? Get a screwdriver and place the tip on the vent screw and the other end to your ear, you should hear it running. Are the zone valves opening? Is there a call for heat? Is the system pressure too low on the domestic side. As you can see there are a few things to check before you get much further.
Most HIU's run like a domestic boiler by using plate heat exchangers to give hydraulic separation between the primary circuit on the district heating system and the domestic house/flat. It should not be a problem for most heating engineers so give someone a call is my best advice to get up and running again.

 

[Matt95959]

Thanks mate, will give that a go. Just out of interest, what do they all do?

 

[johnf]

Do you know what make of HIU it is? Any chance of some photos from a different angle?

 

[Matt95959]

Is the circulating pump running? Get a screwdriver and place the tip on the vent screw and the other end to your ear, you should hear it running. Are the zone valves opening? Is there a call for heat? Is the system pressure too low on the domestic side. As you can see there are a few things to check before you get much further.
Most HIU's run like a domestic boiler by using plate heat exchangers to give hydraulic separation between the primary circuit on the district heating system and the domestic house/flat. It should not be a problem for most heating engineers so give someone a call is my best advice to get up and running again.

Hi John, yes the pump is working and I can feel the water flow though it.

 

[Matt95959]

It's a Danfoss XB 06H-1 26 Heat Exchanger.

 

[johnf]

If you follow the pipe that is hot after the pump do you come to some zone valves? Small box like things

 

[Matt95959]

Do you know what make of HIU it is? Any chance of some photos from a different angle?

Images attached.

 

[johnf]

They are for thermostatic control by the looks of it. You probably have one for DHW (hot water) and one for the heating circuit and then finally one for the bypass. If you do fiddle remember the original settings that you can go back to!

 

[johnf]

bit too small to make out much in the photos even when I blow them up

 

[Sam John Lawson]

Hi there, I'm new to the forum so apologies for any informalities.

My HIU in my flat is receiving hot water from the communal boiler but it's not fully distributing the hot water around the central heating nor hot water taps.

In the attached image there are three adjustable thermostats. Any idea on what regulates what?

Many thanks.

Matt

If you have any questions on what is a heat interface unit and how it really works, perhaps contacting experts to help you out is a good idea. Also, it is important that you avoid playing around with the dials since it might result in bigger problems. You can also search the Internet for various resources about HIUs that can give you more insights about this system. Hope this helps!