Underfloor Heating Died In Wellington. Suggestions Please

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Eva888

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#325030 30-Jun-2026 10:45

Didn’t want to hijack the other Auckland thread. Our Panasonic outside unit just died. Had been making a noise that sounded like bearings gone and it’s about 10 years old so it’s time. It’s a unit that has ducting to half of the house and covers three bedrooms and two minor spaces. Unfortunately we can’t duct to the living area and have a Hi wall Heatpump there that’s useless.

Cowboy installer last time so am unsure if he just decided it was too hard and chose the easiest option or we can somehow include the other areas.

Can anyone suggest someone smart and reliable in Wellington to advise me on new options and possibly a way to extend ducting via the outside so the living area can also get heated from closer to the floor. Also to be able to turn off unused areas. Don’t know if this is possible. In the past we would just close the ducts in the unused rooms and shut the doors.

Hoping to use the ducting already there to save costs and being a Lockwood house there are some limitations. Above all don’t want a noisy unit, the Panasonic was awfully loud. We also have salt laden air. This is a summer house in a winter environment.

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#3507221 30-Jun-2026 11:08

You might want to change the title to make it clearer that it is ducted heating rather than under tile heating.

kiwi_64

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#3507224 30-Jun-2026 11:16

Warmzone do very good work

Eva888

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#3507246 30-Jun-2026 12:26

Bung:

You might want to change the title to make it clearer that it is ducted heating rather than under tile heating.

Darn can’t edit it now but thanks for clarifying for others.

pdh

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#3507296 30-Jun-2026 12:37

If the outlet controls are a pain to adjust (ours were in my parents' 1950's house in Canada) - buy some micro 'Persian' rugs to lay over them. It doesn't take much to shut off a duct's airflow - or to shut it 75% off (if that is what you need) - and shifting a pretty but heavy, A3-sized rug is easier than scrabbling with a flow-control. Just an idea ;-)

tweake

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#3507304 30-Jun-2026 12:59

Eva888:

Our Panasonic outside unit just died. Had been making a noise that sounded like bearings gone Also to be able to turn off unused areas. In the past we would just close the ducts in the unused rooms and shut the doors.

it probably died from running high head pressure because you blocked off the airflow from those rooms.

with ducted it should always flow air through those unused rooms no matter what. if you want to shut off per room then install a heat pump per room.

this is kiwis poor culture of heat per room rather than heating a house. ducted you heat the house, not the room.

pdh

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#3507308 30-Jun-2026 13:02

I know it's too late for the OP - but for anyone reading this thread because they have an interest in central heating for a new build...

The OP's issues of a noisy heat-pump with a shorter-than-expected life in a salty-air environment - and no easy zone control - were the main reasons for me choosing a ground-source water-to-water heat pump. We are 30m from the salt water and our installation has the heat-pump machinery inside - ie: in non-salty air - and it is no louder than our refrigerator. It pulls heat from deep soil warmth (nothing to do with NZ's geothermal energy) and provides 100% of both our hot-water and underfloor radiant space heating.

We have 7 zones upstairs and 4 downstairs (apartment (3) and workshop (1)) - with a simple bi-metallic thermostat in each that just control a bank of solenoid-controlled water valves in the flow piping. If the thermostats shut off all the flow, the heat-pump takes it as a signal that it can take a break from space heating. The insaller guy wanted a 'modern' LCD screen in each zone - with hourly / weekly programming for each zone - but my life is quite complex enough, thank you. On/Off to a desired temperature is just what I was looking for.

The heat-pump accumulates heat (from underground) into a large (but relatively cheap), insulated 1000L tank full of ethylene glycol - as a 'heat battery', using cheap power. Then, even while the heat-pump itself is off, the controller can circulate the underfloor water through SS tubing inside the 1000L tank - and warm the floors - or just produce instant hot water for a tap or shower. Storing heat in a water (well, glycol) battery is cheaper than a Lithium battery.

Unlikely to be retro-fittable, but read up on the concept if you're doing a new build.
It's been popular for decades in Europe & Canada.

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tweake

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#3507326 30-Jun-2026 13:09

Eva888:

Didn’t want to hijack the other Auckland thread. Our Panasonic outside unit just died. Had been making a noise that sounded like bearings gone and it’s about 10 years old so it’s time. It’s a unit that has ducting to half of the house and covers three bedrooms and two minor spaces. Unfortunately we can’t duct to the living area and have a Hi wall Heatpump there that’s useless.

and possibly a way to extend ducting via the outside so the living area can also get heated from closer to the floor.

thats actually a fairly decent way, especially with low/zero insulated houses. that allows you to run lower temps in the bedrooms which most people tend to like. keep the ducted system at a lower temp than the lounge.

i would figure out why your high wall is not working properly.

also what do you mean by "heated from closer to the floor". heat pumps heat you by heating the house first. your not meant to stand in the air flow to be heated. they get their efficiency by pumping out luke warm air rather than hot air. ie lots of airflow. most heat pumps are designed around AVOIDING having people in the airflow.

tweake

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#3507328 30-Jun-2026 13:11

pdh:

I know it's too late for the OP - but for anyone reading this thread because they have an interest in central heating for a new build...

The OP's issues of a noisy heat-pump with a shorter-than-expected life in a salty-air environment - and no easy zone control - were the main reasons for me choosing a ground-source water-to-water heat pump. We are 30m from the salt water and our installation has the heat-pump machinery inside - ie: in non-salty air - and it is no louder than our refrigerator. It pulls heat from deep soil warmth (nothing to do with NZ's geothermal energy) and provides 100% of both our hot-water and underfloor radiant space heating.

We have 7 zones upstairs and 4 downstairs (apartment (3) and workshop (1)) - with a simple bi-metallic thermostat in each that just control a bank of solenoid-controlled water valves in the flow piping. If the thermostats shut off all the flow, the heat-pump takes it as a signal that it can take a break from space heating. The insaller guy wanted a 'modern' LCD screen in each zone - with hourly / weekly programming for each zone - but my life is quite complex enough, thank you. On/Off to a desired temperature is just what I was looking for.

The heat-pump accumulates heat (from underground) into a large (but relatively cheap), insulated 1000L tank full of ethylene glycol - as a 'heat battery', using cheap power. Then, even while the heat-pump itself is off, the controller can circulate the underfloor water through SS tubing inside the 1000L tank - and warm the floors - or just produce instant hot water for a tap or shower. Storing heat in a water (well, glycol) battery is cheaper than a Lithium battery.

Unlikely to be retro-fittable, but read up on the concept if you're doing a new build.
It's been popular for decades in Europe & Canada.

they are really good, but holy cow the price is $$$$$$$$.

tweake

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#3507331 30-Jun-2026 13:14

pdh:

If the outlet controls are a pain to adjust (ours were in my parents' 1950's house in Canada) - buy some micro 'Persian' rugs to lay over them. It doesn't take much to shut off a duct's airflow - or to shut it 75% off (if that is what you need) - and shifting a pretty but heavy, A3-sized rug is easier than scrabbling with a flow-control. Just an idea ;-)

thats a terrible idea.

probably ok in canada as they are probably running a furnace which won't hurt it much. but it will absolutely kill heat pumps.

edit: it also makes heatpumps run less efficiently which defeats the purpose of having them.

pdh

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#3507335 30-Jun-2026 13:22

tweake:

it probably died from running high head pressure because you blocked off the airflow from those rooms.

with ducted it should always flow air through those unused rooms no matter what. if you want to shut off per room then install a heat pump per room.

As a mechanical engineer - with 20 years of growing up in a ducted whole-house forced-air system - I don't agree with this.

If you closed off 50% of the floor outlets, you'd get only a slight reduction in total airflow - just all of it through the remaining (open) 50% of the vents. The airspeed through those open vents would double - with very little absolute pressure rise in the ducting, and hence back-pressure on the heat-pump's fan motor.

If you closed off all but one vent, you might have a problem - but that's not a likely scenario.

With increased airspeed (through the 50% of open vents) will come a slight increase in 'wind noise' - but most of the soft 'roar' coming through air ducting is fan noise, not wind noise.
Or your sister whispering messages after you've both been banished to your rooms.

timmmay

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#3507340 30-Jun-2026 13:37

Have a look at Smart Air Solutions in Porirua, they have great reviews. I haven't used them yet but I'm very likely to for my kitchen replacement.

Also have a read of this thread.

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pdh

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#3507341 30-Jun-2026 13:37

tweake:

thats a terrible idea.

... but it will absolutely kill heat pumps.

edit: it also makes heatpumps run less efficiently which defeats the purpose of having them.

Well, I'm always willing to learn something new... but - please explain why you believe either of these things.

The heat pump refrigeration cycle (compressor motor) is usually in the outside box (subject to salty air) - while the heat distribution fan is fed via hot & return fluid hoses and is situated inside the hose - in the heated space. So the actual 'heat-pump' mechanism could care less what the circulation fan sees in the way of backpressure.

It will have zero affect on its efficiency.

To say that an increase in circulation back-pressure will kill a fan by making it work too hard - is also just unrealistic.
It's what fans do.

pdh

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#3507342 30-Jun-2026 13:43

tweake:

they are really good, but holy cow the price is $$$$$$$$.

You could say the same about a Tesla - hopefully my heating and hot-water supply (for us and our tenants) will be silent and efficient and last longer than the Tesla would.

Eva888

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#3507359 30-Jun-2026 14:42

tweake:

Eva888:

Didn’t want to hijack the other Auckland thread. Our Panasonic outside unit just died. Had been making a noise that sounded like bearings gone and it’s about 10 years old so it’s time. It’s a unit that has ducting to half of the house and covers three bedrooms and two minor spaces. Unfortunately we can’t duct to the living area and have a Hi wall Heatpump there that’s useless.

and possibly a way to extend ducting via the outside so the living area can also get heated from closer to the floor.

thats actually a fairly decent way, especially with low/zero insulated houses. that allows you to run lower temps in the bedrooms which most people tend to like. keep the ducted system at a lower temp than the lounge.

i would figure out why your high wall is not working properly.

also what do you mean by "heated from closer to the floor". heat pumps heat you by heating the house first. your not meant to stand in the air flow to be heated. they get their efficiency by pumping out luke warm air rather than hot air. ie lots of airflow. most heat pumps are designed around AVOIDING having people in the airflow.

The room with the heat pump has high chapel ceilings. The heat pump sits up too high so by the time the heated air reaches the person sitting or the ends of the room, it’s cooling and breezy. Can’t put it any lower as no wall area. The room is warm except from knees to floor level. Floor area is cold. This is why I wondered if the bedrooms ducted could be extended to a low part of the living room by going in from outside.

As for the bedroom vents, even closed they would leak enough warm air into the unused bedrooms, they aren’t airtight. I did it to push more air into another duct that was added into the corner of the living area by someone else, but that was pretty useless. Original installer was a crook who took advantage of our trust and left us out of pocket to boot.

The entire system needs an audit.

tweake

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#3507367 30-Jun-2026 15:10

pdh:

Well, I'm always willing to learn something new... but - please explain why you believe either of these things.

The heat pump refrigeration cycle (compressor motor) is usually in the outside box (subject to salty air) - while the heat distribution fan is fed via hot & return fluid hoses and is situated inside the hose - in the heated space. So the actual 'heat-pump' mechanism could care less what the circulation fan sees in the way of backpressure.

It will have zero affect on its efficiency.

To say that an increase in circulation back-pressure will kill a fan by making it work too hard - is also just unrealistic.
It's what fans do.

put some gauges on it and i think you will be surprised.

ask any good refrigeration guys, airflow is king. indoor coil airflow makes a huge difference to the refrigeration cycle. excuse me for skipping tech details here as its to long to post. the lack of cooling of gas in the coil means the compressor runs at higher pressure, requires more power to drive it, which's costs more. airflow has a direct effect on compressor head pressure.

in real world, i just had it at a mates place. he had issues with his running because he had the fan on low speed. i've had it with mine where it had a fault code, because of dirty filter (opps) so it wasn't getting enough airflow.

heat pumps typically get their efficiency from running a lower delta t across the coils. to do that requires higher air flow compared to say a furnace. lower the airspeed the higher the outlet air temp is, but higher refrigerant temps which takes more power to compress. so less airflow means performance reduces, running costs go up and lifespan reduces.

fans are not always designed for high back pressure. a lot are designed for efficiency which is king with heat pumps. so airflow can drop dramatically with restriction. with some you can increase the fan speed to compensate. closing off 50% is bad, 75% is a downright killer. also the more pressure you runs the more air leakage you get, which on a ducted system in the ceiling can depressurize the house. this is why design is so important but sadly rarely done.

if you want to block outlets, then you need a spill aera you can dump the airflow. frankly its better to simply not block it off and heat the home properly. its not like the heat is going to be unused.

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