Heat Pumps - post here.

Sponsorgate

https://www.boards.ie/discussion/comment/121660138#Comment_121660138

Thanks for your reply. The max i can set it to using the control panel is 50c. That's why I'm not sure it jumps to 53 on some occasions.

Cyrus

https://www.boards.ie/discussion/comment/121660411#Comment_121660411

The 53 id guess is post a legionella cycle but as i said it tends to fluctuate around the temp you set to a max and min so that could be it either,

is it capped at 50 degrees? didnt realise that, have you seen this

https://www.youtube.com/watch?v=yTBPtHJv-wU

or is there anything in the manual to help

https://www.cairnhomes.com/media/kwqde4nb/joule-heat-pump-installation-manual.pdf

it looks like the max DHW temp is in menu 3021 (see page 5) and its default value is 50 id assume you can increase that, see page 30 for how to get in that menu area (its explaining how to get into the 20 section but one more push up brings you to 30)

hopefully that helps!

graememk

https://www.boards.ie/discussion/comment/121660411#Comment_121660411

I'd be more inclined to look at the shower. Is it up full? Have you pressed the button that is on some to allow it to be hotter?

championc

https://www.boards.ie/discussion/comment/121659380#Comment_121659380

Two things spring to mind

1. To get to 53, I wonder if the immersion is on a timer, doing a night time boost, maybe at a cheap rate ?

2. Does your hot pipe have an anti-scald valve, which is mixing cold water to lower it for a sub 48 water delivery to the taps, and this could be set too low.

Sponsorgate

https://www.boards.ie/discussion/comment/121660663#Comment_121660663

Thanks very much Cyrus, great info.I had seen the video before which allows max 50c similar to my own. I haven't tried what you explained in the manual. i will give that a go for sure.

Sponsorgate

https://www.boards.ie/discussion/comment/121660950#Comment_121660950

Yes shower is up full. When we have a shower when the temp is approx 50 or slightly over, its perfect.

Sponsorgate

https://www.boards.ie/discussion/comment/121661564#Comment_121661564

Yes , this my initial thought regards your first point. But it doesnt jump to 53 every morning. Only some mornings. I haven't noticed a pattern.

2nd point- I don't know but I dont think so. Because we have had showers that we wouldn't need the shower turned up full. Just need to find that happy medium some how

championc

I would expect the legion Ella cycle only once per week.

Scalding point is in the mid to high 40's. So while the system indicates 50 Deg and over, there is no way that you could have full hot, unless there is an anti-scald mixing valve in the line

graememk

At the kitchen tap how hot is it?

If the shower was putting out 50c you wouldn't be able to stand under it. It's been mixed down.

Possibly the shower isn't setup correctly, any thermometers in the house? ( And measure the temperature of the water at shower, tap, kitchen)

johndoe11

My hot water is set to heat to 55, but that setting isn't the actual hot water temperature, but the heat pump DHW flow temp. At 55 it heats to about 47. Once whats described as the "heat carrier" reaches 55 it shuts off. Not sure if it is maybe the same setup.

NedNew2

I have the same system. From what I understand, the heat pump will only heat to 50 after that the back-up heater (basically an immersion) takes over.

HotSwap

https://www.boards.ie/discussion/comment/121659380#Comment_121659380

Can’t you just use less cold water at the shower head? Your not atcually spraying 50c water onto your body:

At 60°C, it takes one second for hot water to cause third-degree burns. At 55°C, it takes 10 seconds for hot water to cause third-degree burns. At 50°C, it takes five minutes for hot water to cause third-degree burns.

what kind of shower valve is it?

grahamt311

Hi

I'm new to this whole heat pump, I have moved to a brand new house with a Toshiba yutaki air to water heat pump. Previously had a house with solar PV and gas boiler, so still trying to get my head around the heat pump.

We didn't get much off a hand over from the installers but it was set to fixed 50 degrees for both dhw and flow temp.

I have since been tinkering with weather compensation setting and lowered the dhw to 45 degrees

The system is always on and downstairs it set to 20 degree while upstairs being 16

We only have radiators I have my minimum flow temp at 35 at 15degress and max at 50 at -2 degress. Seems to be working good, especially in the cold weather. Does the kWh I'm using seem to be high, I know it's got to work harder in the cold I just thought it would be more economical to run. Any advice would be great

Also that is a 2 adults and 2 toddlers. 1 working from home

HotSwap

https://www.boards.ie/discussion/comment/121664216#Comment_121664216

Can you show your COP?

If you have TRV’s on your rads set them all to 5.

Id set both of the stats for upstairs and downstairs to 21.

did you set your flow temp curve from fixed to weather comp before the chart data above?

grahamt311

I have no idea how to check the COP..

All the TRVs are are set to 5.

That's when it was set, the one attached now is when it was fixed, I know it's not a lot of data..

The whole heat pump is a lot to get your head around when your switching from gas.

When it was fixed the house was just getting to hot not it seems to have steady not getting to hot or warm, I'm just more curious about the energy usage

championc

You are now likely changed over from running "an hour in the morning and a few hours in the evening" type of operation, to suddenly running 24 hrs.

Of course, you are therefore not comparing apples with apples.

So your setup could be quite efficient, but that's not saying it's more economical (which really is your point).

I have a plan to run the heat pump like a gas boiler - running for "an hour in the morning and a few hours in the evening" type of setup.

Running 6 hours at 2kW is surely better than running 24hrs at 1kW. Might be worth experimenting to see what usage would be like for this type of operation.

MagicBusDriver1

https://www.boards.ie/discussion/comment/121664216#Comment_121664216

In a new house you should be able to get much lower than 50 degrees at -2. I would keep reducing the slope.

grahamt311

Thats literally how I felt like it was set up initially to be like a gas boiler, which I thought was wrong. It would be interesting to see how it would work if I set up timers like how you mentioned. I'm quite happy with the set up as in the house is always pleasant plus the wife works from home and likes it warm. Just seems like it's using a lot of electricity maybe I just have to get used it that now not having a gas bill

HotSwap

https://www.boards.ie/discussion/comment/121666143#Comment_121666143

I just realised that the screenshots your sending are taken from the electric Ireland web portal; and they are representing the total energy usage in your house; not just the heatpump.

were you away 13th-19thNov? Those days are very low.

Do you have any stats directly from the heatpump?

grahamt311

That was before we moved in and had not got the heat pump on. The first big spike is when we moved in. No I've nothing telling me directly how much the heat pump is using, hoping the houses smart metre can tell me after the 4 month period it takes to register appliances on the system.

championc

You could look at getting a Shelly EM to monitor the heatpump consumption

graememk

https://www.boards.ie/discussion/comment/121666783#Comment_121666783

Register for the esb networks so you can get your 30 min use. (And I don't really put much faith in the appliance use guessor)

What heatpump do you have, does it have a screen, can you pull up any information on it.

HotSwap

https://www.boards.ie/discussion/comment/121666783#Comment_121666783

It won’t. That’s a load of nonsensical marketing. The smart meter has no way of knowing what is using the power.

You would be best served by finding the section of the control panel that shows you historical power usage and COP values. If you post that we can advise you.

Although to give you some indication; considering an average house can use 15-20kwh per day. And you’re using 35-40kwh on the coldest days. That would leave you somewhere 20-25Kwh per day for the heatpump. Which is far from the worst I’ve heard of.

newhouse87

How big is the house?

grahamt311

The house is a 145sq m 4 bed corner house. I had a look to the settings and managed to get this up seems about right if you compare to the usage on my bill. Seems to be down around 20kwh on the heating and between 1 and 2 kWh on dhw at the minute. Would that be good or bad.

grahamt311

The heat pump is a Hitachi yutaki s.

graememk

https://www.boards.ie/discussion/comment/121667723#Comment_121667723

Does it show output power too?

Output divided by input is the COP

HotSwap

https://www.boards.ie/discussion/comment/121667712#Comment_121667712

If you keep looking you will find COP or SCOP or heat generated. Your system could be operating very inefficiently and outputting 2kwh of heat for each 1kwh of electricity. On the other hand it could be outputting 3.5-5 kWh of heat for each 1kwh of electricity.

the only way we can know is by knowing this data point from the settings. If you’re operating at a lower COP 2-2.5 it’s likely you could make more adjustments that would improve that efficiency. If you’re already operating at a COP of 4 for example. You’re doing amazing. It all depends.

newhouse87

https://www.boards.ie/discussion/comment/121667712#Comment_121667712

Seems bit high for house size. What temp is house at?

grahamt311

Ok I think I have it figured out how to work out the cop. Divide the capacity by the input?? If so it seems to range in and below 2.5 on the colder days and up above 3 when it's milder would that be right. That's for the help the plumber who installed doesn't want to know