Heat Pumps - post here.

Tar.Aldarion

Just new to air-to-water heating and have the tank set to 60 degrees, have noticed it rarely gets to that temp, mostly hangs around in the low 40s - should it be hitting that temp, what temp should it be usually? I notice on cold days like the past few it works poorly with the temperature now in the 30s, which also makes for luke warm showers instead of hot etc. What temps should the water be?

The house also cooled from 20 to 17 degrees even though the heating is on. Is that usual or an issue? Would have thought it should be able to handle this, especially as it's when it's cold is when we actually need it.

Here is mine: https://cool-energy-shop.myshopify.com/products/cool-energy-ecostore-ce-es300-all-in-one-heat-pump-hot-water-system?shpxid=9b5ab9b5-c4dc-48b3-9c62-2027937acb63

It serves both hot water and central heating, I think there are two tanks and sometimes they mix if there is heat disparity, not sure of the inner workings. Sometimes it will go into legionella mode and try to heat the water to 70, however since it never reaches that temperature ever it will be stuck in that mode forever unless I turn the thing on and off. It has an immersion for cold weather which I leave on.

KCross

@Tar.Aldarion It shouldn't behave like that. You should have piping hot water if that's what its setup to do. The house dropping to 17°C also isn't right/normal/acceptable.

You need to get an engineer out to look at the system and see if the settings are right or if it has developed a fault.

Any red lights or warnings or alarms on the screen of it? Either way, get someone out to look at it.

Mickeroo

@Tar.Aldarion Is that tank in your link the entire system or is there a separate heat pump outside? The device you linked to doesn't sound like it's designed to provide central heating to me, just domestic hot water?

This would explain why it's struggling to get up to temp imo.

Tar.Aldarion

https://www.boards.ie/discussion/comment/120124016#Comment_120124016

It's the whole system, I mentioned this to the boiler company I have, they said they designed this system with the manufacturer company and although it says that in the docs in reality they work fine to serve a house for both. Yet the guy who built this house has the added separate heat pump in his own house!

https://www.boards.ie/discussion/comment/120123937#Comment_120123937

Thanks, the boiler is currently plumbed wrong and can only serve one zone at a time, when the plumber fixes that I'll get on to the boiler company too. No warning signs, maybe the immersion switch dial is set too low or some other setting is wrong.

Nelbert

The air flow spec from that manual is the equivalent a couple of good bathroom extractor fans.

Most people will have a unit that size inside and another unit with a very big fan outside.

It explicitly says it's only for hot water....

Its being asked to do way too much to run the heating circuit hence cold showers and house.

I don't know the installer but it seems you've been sold something not fit for purpose if you were looking for central heating. It's intended for exhaust air from a heat recovery system to use the excess heat in your home (kitchen and bathrooms) to heat the water up.

The "fan" part of my heat pump outside is over 3 foot high and about 4 foot wide. Think of the air it can pull through Vs a couple of pipes through the wall.

Its water heating energy efficiency from the spec sheet is awful by comparison to most heat pumps as it's intended for a very specific setup.

Rated Heat Pump Output - 1.527kW

My heat pump is 11kW and the immersion heater in it is 3kW....

newhouse87

Bit of an odd question, my kwh usage on heat pump mental. Sitting room in particular always calling for heat and never gets to 21 and i have just turned it off now. Essentially When the sitting room calls for heat the utility next to it has no heat change as its ran on kitchen stat but the main bathroom beside utility gets v warm. Is it possible that my sitting room stat is heating the ufh in my bathroom while by passing the adjoining utility and heating bathroom. IM starting to think the sitting room stat is just heating bathroom and not the actual sitting room its meant to heat. Cant understand how pipes would be laid out that the sitting room pipes get warm, adjoining room by passed and then main bathroom warm.

Nelbert

Absolutely possible. A bit of mislabelling on pipes and / or stats and the wrong stat gets connected to the wrong actuator.

Had this issue with a 2 upstairs bedrooms being mixed up.

newhouse87

https://www.boards.ie/discussion/comment/120125455#Comment_120125455

Is there anyway to check this or fix it? been driving me mad with months, had stove in sitting room so just presumed that room would never get up to21 with flue, but the bathroom would get roasting as sitting room stat was calling for heat for days on end. I coud see 2 actuators up and flow going when sittng room stat on but only bathroom which has no stat seems to warm up.

graememk

https://www.boards.ie/discussion/comment/120125613#Comment_120125613

Process of elimination. (Thermal camera would be SUPER useful, but even a cheap IR thermometer should do it.. or even your hand)

Turn all stats off.

I assume there is a manifold.

Turn on one stat, See what pipe gets hot coming from the manifold.

Then see what floor gets warmer.

Its much easier with rads!

newhouse87

https://www.boards.ie/discussion/comment/120125717#Comment_120125717

yeah have manifold and when sitting rooms stat comes on, 2 actuators pop and flow rate starts. Hard to feel the timber floor for heat in that room but i know by temp not increasing something is wrong and bathroom floor gets hot. Dont know why they would have rigged sitting room and bathroom on same stat as them rooms not near each other. Kitchen stat does utility and hallway and half way up is the bathroom which come son when sitting room beyond kitchen calls for heat. Can this be easily rectified?

micks_address

Am I right in thinking that the 4 to 500 percent efficiency quoted often for heat pumps drops much closer to 100% when the temp is cold outside way around 5 degrees or lower?

Nelbert

The manifold, stats and actuator issue is easily rectified but the key bit the process of elimination to understand which run from the manifold is heating what room. One stat at a time, what heats up in terms of pipe at manifold and floor of room.... Once that's done its hopefully just a case of unscrewing actuators and putting them on the right manifold section. Doing this way avoids any need to touch stats or electric side of things.

Nelbert

https://www.boards.ie/discussion/comment/120125801#Comment_120125801

No. I was at about 250% yesterday. Flo temp of 42 and outside temp was 2 or less where I was when heating was running.

Edit: actually temp was below 0 for most of that looking back.

newhouse87

Thanks for all the info here. Had guy out servicing my boiler yesterday too and was telling him about kwh usage. He said my dhw temp at 50deg was too hot and i should bring it down to41, Anywhere i read online it says 50. Was his suggestion correct? Tried it on my daikin and put to 41 but it keeps going back to 50 after a while.

Nelbert

If you had it at 41 and like a piping shower you'd be disappointed.

Mine is set at 50 gets with a slightly increased offset to 12 instead of 10 so it heats back up to 50 when it gets to 38 not 40.

Legionella Cycle brings it to 65 every 15 days.

My hope is to get some solar and an Eddi and have hot water in the summer taken care of by the immersion.

The mornings after Legionella Cycle gets us 2 piping hot showers and back to 50⁰ so my thinking is an Eddi to target 65 would eliminate almost all hot water.

edit: To clarify immersion in the internal unit of the heat pump via Eddi is the plan. Heating installer sent wiring diagram for sparks whenever I fulfill my solar dreams.

johndoe11

https://www.boards.ie/discussion/comment/120125801#Comment_120125801

The reason the cost adds up is not so much efficiency it is that the compressor needs to run much closer to 100% for longer periods when it is around zero. I have disabled the auxiliary heater as well. Also less than zero, they have to defrost themselves very frequently. Here is my compressor speed, output vs outside temp over the last day or so. As you can see, It was stopping to defrost very frequently. Still a great system, once you get used to very high winter bills.

Screenshot_20230118-194050_Home Assistant.jpg

ConorC1

https://www.boards.ie/discussion/comment/120121476#Comment_120121476

They are not labelled unfortunately. Getting a radiator key tomorrow so will find out what zone they are heating with a bit of trial and error. Was thinking I could reduce the amount of water going to the zones with the tiles so as more will go to the zone with the engineered wood floor?

KCross

https://www.boards.ie/discussion/comment/120125801#Comment_120125801

It depends on the type of heat pump.

Air-to-water systems will go to <100% efficient in really cold weather as they have to use up energy to defrost themselves.

Ground source systems dont suffer from that as the cold/frost doesn't affect the pipes under the ground. e.g. it could be -5°C outside in the air but the pipes under the ground are sitting at 5-10°C so that's an immediate gain of 10-15°C that the ground source system does have to "find" relative to an air-to-water system.

Ground source should provide a COP of 4-6 during the winter. This makes it a more efficient and longer lasting system as the compressor is under less stress when heat is needed the most. The downside is they cost more to install. Thats a balance you have to strike when you are installing.... unfortunately most people go for the cheaper install option because its the cheaper quote they have, rather than looking at the lifetime cost.

Of course, some sites just dont have the space to install ground source systems, which is fair enough too.

Nelbert

https://www.boards.ie/discussion/comment/120126316#Comment_120126316

Actuators (that I've seen) are just open or close they don't control the volume of flow.

You'd most likely be best to split them to seperate zones with their own stats which will control how much heat one gets Vs the other.

Assuming they are on seperate manifolds.... Which seems like they should be.

the_amazing_raisin

https://www.boards.ie/discussion/comment/120125801#Comment_120125801

A properly designed one should still have a COP over 1 in cold weather

Mine unfortunately doesn't have the ability to read the COP but I remember I calculated it a while back and it was fairly close to what the manufacturer was saying, around 2-2.5 for this weather

As others said the defrost cycle uses some energy, mine takes the water from the buffer to do this so it has to recharge the buffer again afterwards

If it can supply enough heat without using the backup heater then it should stay pretty efficient. Avoiding the heat pump cycling on and off seems to be key as well

Having the flow temp low and long heating cycle seems to be the answer to that

graememk

https://www.boards.ie/discussion/comment/120125787#Comment_120125787

Before Rectification, Try and figure out all the "knowns" The more knowns you know the easier it is to narrow down the problem.

Ie if you turn on the sitting room stat Bathroom gets hot. but Not the sitting room. - bathrooms are usually kept warmest as your usually wearing less clothes! Sitting room would usually be used most so would be wise to put it on the same stat.

Where else heats when that stat is on?

If you can figure out what stat does what, you'll be onto something.

Is there any stat you can turn on that heats the sitting room?

https://www.boards.ie/discussion/comment/120125801#Comment_120125801

It all comes down to the difference in temperature.

The data sheet of the ecoforest

The COP Air7Water55 is 3

If air was 0 and water 49, it would still be 3

newhouse87

https://www.boards.ie/discussion/comment/120126692#Comment_120126692

The sitting room stat seems to just make bathroom hotter and sitting room temp doesn't rise with any stat. Utility which is between bathroom and sitting room gets hot with kitchen stat which is adjacent to sitting room. surely the the pipe run couldn't be that short to run from plant room to bathroom beside it and back again when i turn on sitting room stat.

graememk

https://www.boards.ie/discussion/comment/120127815#Comment_120127815

Then is there any of the valves that dont click on when a thermostat is used?

How many loops are there in the manifold?

How does that compare to the number of rooms in the house?

How many Stats is there in the house?

When the sitting room stat is used, you said 2 things on the manifold clicked on,

Did both get hot?

Could you find the corresponding return pipes for them, (they should be in the same position on the return manifold)

(also when not using the stove, make sure all the air vents are closed)

Nelbert

Pics of the manifold would help.

Number of stats downstairs?

You could have broken actuators, stat linked to wrong actuator.

Poblem definition is important. First thing is it seems your kitchen stat controls the bathroom actuator. But it's the rest of the config that needs to be established before you go swapping anything. The actual fix could take a minute or two once you nail down the problem.

Runs can be long or short. Downstairs I've 6 runs, 1 for hall, 1 for sitting room, 1 for utility and connected bathroom and 3 for the kitchen / living room area (50m² for this room hence multiple runs I guess).

newhouse87

https://www.boards.ie/discussion/comment/120127881#Comment_120127881

I will look into all that, thanks for info.

newhouse87

https://www.boards.ie/discussion/comment/120127981#Comment_120127981

Its a bungalow 7 stats in total.Im going off to Vegas in the morning so will take pics of the manifold when im back next weekend. Appreciate all the help here. The lad that done my boiler who told me he would explain everything was pretty useless and cost me 250eur for an hour of his presence.

THE ALM

Bit of a piece of string question but how many hours, heating, would a heat pump normally run in a day?

Doing a bit of experimenting here by lowering the temp of the boiler to see how long it would run to maintain a set temperature. Normally just have it timed to run in the morning and evening but have added a Shelly on the boiler so I can see when it is actually firing.

Thanks

Stefs_42

Hi Guys,

Need some realistic advice from ye who have heat pumps or SMEs in the field would be greatly appreciated. Been planning to install HP for a good while now and done some home work on heat loss. Ive been told my house is draft proof enough to have a HP system. But I want to hear from regular users, rather hearing from salesman.

I have regular semi detached double glazed house with pumped walls and insulated attic. Kitchen has underfloor heating, rest of the hour - regular rads.

Question: is it really necessary to have tripple glazed windows and if not underfloor heating, then aluminium rads are advisable? What would be realistic HP running costs compared to oil heating. (I use around 1000 L of oil per year)

the_amazing_raisin

https://www.boards.ie/discussion/comment/120130684#Comment_120130684

So you don't need triple glazing, I have double glazing and it's fine

Having said that there's different levels of heat conduction for double glazing, so it's not necessarily the deciding factor

It sounds like your house is reasonably well insulated, so you should be within the range of a heat pump being economical

You probably want an engineer to assess your house, check the level of airtightness and also check if the emitter sizes are up to scratch

For me, I reckon the heat pump uses around 4,000kWh per year, probably the majority of that at night time

So about 2,500kWh at 13.75c/kWh and the remaining 1,500kWh at 47.77c/kWh (ugh) gives about €1,060 per year

If you have solar PV then that will be a bit lower

No idea how that compares to oil, I know some folks have energy monitors on their heat pumps so they'll be able to give a much better answer

Nelbert

My heat pump used just under 600kWh in November and December combined. That's for heating and hot water and probably 85%+ was on night rate (would have been 90+ bar those really cold December days). Probably about 200 m² house. A3 rating post refurb. Triple glazing with UFH downstairs. Well insulated but a bit of remedy work due on air tightness (mainly around vents in a few rooms).

Everyone's insulation levels, air tightness, glazing etc. And the quality of installation of all of that and the heat pump are a factor, as well as the installer knowing the unit they are installing well to configure accordingly.