Recently purchased house - help required re heating

funnyname

Hi

Just need a little advice, we recently bought a house that was built circa 15 years ago.

I've read a few interesting threads re heating but I wanted to create my own as there seems to be a lot going on.

There are 5 heat sources

1. Solar tubes
2. Stove - Charnwood country 15b (output of 13 kW to water and 2.5 kW to room)
3. Oil range in the kitchen
4. Oil burner
5. Heat pump

They all contribute to a 1000ltr tank that's in the house.

There is underfloor heating throughout the house although it seems it wasn't great upstairs so rads were installed in all the rooms afterwards.

There are also 2 rads downstairs, one floor to ceiling in the hall and one in the family bathroom.

There are thermostats in all the main rooms but upstairs the rads have their own thermostats so the ones for the UFH are turned down as there's no need for that to come on.

We've used everything bar the oil range in the kitchen as it needs to be serviced and have the flow tinkered with as it produced a yellow flame when we lit it and burned itself out.

There are 3 temp gauges in the 1000ltr tank, bottom, middle and top. There are a lot of pumps in the same room as the tanks for all the systems, and there is also one with a manual switch for transferring hot water from the top half of the cylinder to the bottom half.

Kinda at a bit of a loss as to how to get the best use out of all of them now that winter is upon us.

The solar has been great but I doubt we'll see much input from it over the next few months.

The heat pump when used (I currently have it timed to come on between 1am and 7am) to heat the tank only, gets the top half to about 48 degrees. Which is ok for showers in the morning, however last week I also added in the UFH and water was very lukewarm, I guess most of the hot water went out into the UFH tubes.

We've had a full fire on over the weekend and the hot water generated was excellent, I turned on the rads were scorching from it.

We also have the oil burner on as well but only to heat the water in the tank and this gets it up to about 60.

So I guess my question is what's the best combination to use for heating the house and providing plenty of hot water for an average size family?

Thanks for reading I hope I've put down enough info, if not please ask for more.

Regards

FN

antoinolachtnai

You are doing what I would do, starting with the things that look cheapest and easiest and working to the more expensive and awkward looking.

Who knows really though? It is a really complex system. Obviously it isn't much help for you but I wonder if people would be better with much better insulation and much simpler heating systems.

I would suggest running the heat pump for the full 8 hours of nightsaver electricity while you are at it during the cold months, rather than for just 6 hours. There may be some reason why this is not a good idea, but I don't know of one.

I would suggest trying to figure out a diagram of how the whole thing is plumbed.

I would take some time taking evening and morning readings of the temperature gauges and the electricity meter so you have some figures to document your experiments.

funnyname

It was a very sunny day in Clare so the solar got the top of the tank up to about 60 degrees and the bottom to about 40. With this, I put on the underfloor for a few hours as it got cold in the evening. We also put on a handy fire however it would seem that it only heats the top half of the tank as of now it stayed at around 60 and the bottom went back down to 20.

Tonight I will have the heat pump set for 12am to 8am and I will run the underfloor heating from for the same time and see how much hot water is in the tank when we get up.

there is a salus 300 digital thermostat in the kitchen but dial ones in the rest of the rooms. There are 4 zones downstairs and 4 upstairs (although upstairs are now redundant given that the rads have their own thermostats).

I think it would be a good idea to replace the 3 dial thermostats downstairs with digital ones for higher accuracy, how easy is this to do, diy or an expert?

I will update with readings in the morning.

funnyname

I just turned on the pump that circulates water from the top of the tank to the bottom and it didn't kick in. I did it over the weekend and it worked fine. The temp differential at the moment is 40 degrees, surely that's enough to make it kick in. I'll try it again tomorrow.

Also is it best to keep the bottom of the tank at a minimum temp?

funnyname

This morning at 7.45 I looked at the tank and top was 38 and the middle and bottom gauges were 28. The tiled floors (downstairs) were warm however the water wasn't really hot enough for a good shower.

Looks like we'll need to have have the oil burner kick in for a bit in the mornings to get the temp up a bit higher.

antoinolachtnai

You could change the thermostats downstairs, but honestly, I wouldn't bother. It won't necessarily be much more accurate. Unless the property you have bought to live in in Clare is actually Shannon Airport, 8 zones is an awful lot.

If I were you I would save the money to go into some sort of master controller at a later date to let the whole thing be managed a bit more automatically.

I'd be guessing that the UFH coil probably goes from further down the tank, rather than from the top of the tank. That is why you need to have some warmth throughout the tank. But I am really only guessing.

The coil from the fireplace is probably quite high up in the tank. That's why it only heats the top part. I'd be guessing that the heat pump is piped into a coil at the bottom of the tank, the solar into one in the middle and the boiler and fireplace into one at the top. But that is just my guess. You really need to figure this out. I suggest you draw some diagrams of how the system is put together.

To find out why the pump won't run, you will probably have to learn how to use a tester screwdriver, to trace how the thermostats are connected together and see whether power is getting to the pump, or if the pump is faulty. You can buy a tester screwdriver in any hardware store, but you need to be very careful in its use if you are not familiar with dealing with live voltages. An electrician, but really anyone reasonably handy, will be able to show you how to use it to trace a fault in the pumps.

How you run this is going to depend on your lifestyle. If you are out all day, it might make more sense to leave the heat from the heat pump to build up in the tank overnight, then run the UFH during the early afternoon, so the house is warm when you get home.

antoinolachtnai

Make sure to keep an eye on your overnight electricity consumption. You have a day/night meter?

funnyname

Thanks for those suggestions, I will try and do a diagram and I might post some pictures of the controls/pumps in the tank room when I get a chance.

Is there much to installing an automated control system, I read a thread a while ago that referenced it but I can't find it now

We do have day/night rate, we used 36 units of electricity between 12am and 8am but the washing machine and dishwasher were delayed to come on during this period.

antoinolachtnai

36 units is a fair chunk of electricity. It will cost you €3.60. If you keep using that much every day between now and March, it will cost you 180 x 3.60 = 600 euros or so. The washing machine and dishwasher wouldn't account for much more than 5 or 6 units of that (though maybe it is worth keeping an eye on them some day to check).

You might get almost as much heat from running it for a shorter time, I don't know (though it would be worth trying out).

How big is this house? Does it have a BER rating?

funnyname

The house has a rating of b3, attic accommodation with velux windows. Normal windows in upstairs gables. Its about 2200sqft.

antoinolachtnai

worth looking at http://cygnum.ie/updateAdmin/uploads/Building-Energy-Rating-Guide.pdf

This indicates that at that size and rating, you should be looking at a heating bill of around 1600 euros for heating and lighting. It is just a very rough guide, but might be helpful. In the context of this, I suppose 36 units of electricity at night isn't too bad.

I suppose this would imply that you could expect to heat the house with the heat pump running at night and a tank full of diesel every year.

Re setting up a controller, there are plenty of controllers on the market, but the real issue is what do you want the controller to actually do? That is what you are working out at the moment. In a few months, you will be in a better position to get a controller set up.

Basically a controller is just wired in to turn the switches you are currently turning, but automatically, on some sort of schedule.

funnyname

Thanks again

last week we used 255 units of electricity, given the morning readings I would say 75% if not 80% of this was used by the heat pump and ufh system.

I will tweak the times it comes on for and see how that works. Still great weather so solar is providing a bit of hot water.

We have a fire on tonight and I tried the pump for circulating the water from the top of the tank to the bottom and it kicked in so I presume it only works when hot water is being added to the tank.

I guess it's that kinda automation I'd like to have and also to have a minimum temp of water in the tank so that we have hot water whenever it's required.

Like this evening before the fire was on I gave one of the kids a bath so I checked the temp of the water and it was only about 40 degrees so I put on the oil for a bit.

I remember reading another thread about this kinda solution but I can't find it again.

antoinolachtnai wrote: »

worth looking at http://cygnum.ie/updateAdmin/uploads/Building-Energy-Rating-Guide.pdf

This indicates that at that size and rating, you should be looking at a heating bill of around 1600 euros for heating and lighting. It is just a very rough guide, but might be helpful. In the context of this, I suppose 36 units of electricity at night isn't too bad.

I suppose this would imply that you could expect to heat the house with the heat pump running at night and a tank full of diesel every year.

Re setting up a controller, there are plenty of controllers on the market, but the real issue is what do you want the controller to actually do? That is what you are working out at the moment. In a few months, you will be in a better position to get a controller set up.

Basically a controller is just wired in to turn the switches you are currently turning, but automatically, on some sort of schedule.

antoinolachtnai

The use of the pump to mix up the water is a very interesting issue.

http://www.navitron.org.uk/forum/index.php?topic=10739.0

What benefit does it bring when you run the pump?

You should see if there are any thermostats wired to the pump.

funnyname

With the solar and heat pump feeding the bottom half of the tank and the UFH being fed from there as well, I'd like to circulate the hot water from the top of the tank (after a good fire at night) so that I don't need to run the heat pump for as long in the morning. Is this possible or am I being too optimistic?

antoinolachtnai wrote: »

The use of the pump to mix up the water is a very interesting issue.

http://www.navitron.org.uk/forum/index.php?topic=10739.0

What benefit does it bring when you run the pump?

You should see if there are any thermostats wired to the pump.

antoinolachtnai

Not sure really. In general though, the heat pump should be the cheapest source of heat you have. You want to use this in preference to the oil or the fire. I would be inclined to run the heat pump anyway and try to light a smaller fire the next day, or maybe light it a bit later. The water at the hot of the tank will probably get used up the next morning for hot water, as the amount of solar water heating decreases over the winter. But it is really a matter of what suits your lifestyle.

funnyname

Thanks again Antonio

Sure it'll be trial and error over the winter to find the best combo.

funnyname

Not the greatest of heat provided by the heat pump, as far as I can tell it is a

Phoenix P400


google search yields nothing

https://www.google.ie/?gws_rd=ssl#cr=countryIE&tbs=ctr:countryIE&q=phoenix+geothermal+heat+pump+p400

anyone here able to direct me to any sort of info on it?

Many thanks

antoinolachtnai

It is worth reading more about how the heat pump works. The heat pump doesn't itself produce the heat. It just moves the heat in from the collector, which is buried in your garden.

Where does the collector get its heat? Most likely it gets it from the heat of the sun. (some collectors get heat from geothermal sources, but this is not likely in your domestic scenario). As the weather gets colder there is obviously less heat from the sun. It may well be that the collector is smaller than it needs to be. But it is hard to know.

I wouldn't say there is much wrong with the heat pump itself.

Tommyboy08

funnyname wrote: »

Not the greatest of heat provided by the heat pump, as far as I can tell it is a

Phoenix P400


google search yields nothing

https://www.google.ie/?gws_rd=ssl#cr=countryIE&tbs=ctr:countryIE&q=phoenix+geothermal+heat+pump+p400

anyone here able to direct me to any sort of info on it?

Many thanks

Can you post a pic of the unit, is it air or ground source?

funnyname

Here are a couple of pictures of the unit

funnyname

Hello there, back again after our first winter in the gaff.

See attached photo for set up of thermal store.

Oil burner and back boiler circulate the top half of it and solar and heat pump the bottom half. There is a pump to circulate the hot water from top to bottom but only when the back boiler is adding to the store.

We find that the heat pump heats up the water to back 45 degrees at the top of the bottom half and about 42 at the bottom, without any source drawing from it. However when the underfloor is on for 5 or 6 hours the water doesn't go up much higher than 35. Also there only seems to be one stat that calls the heat pump. A friend who had a much more modern system (waterkotte) with the outside temp and a few other triggers inside the house).

When I had the time I put on a fire in the morning and circulated the hot water from the top to the bottom as the it gave more heat to the underfloor and cost less due to the day rate kicking in for the geothermal.

I have a plumber coming in a week or two to do a review of the setup and also suggest some better controls as it's all very manual at the moment. I'd like to add an automated control system like one available from Conrad or Climote.

Any suggestion re what I should get the plumber to look at/investigate and and ideas on an automated system that would work well for a house with underfloor downstairs and rads upstairs and 4 different heating supplies.

Also there is underfloor upstairs but seemingly that was too far away from the timber floor and didn't heat the rooms adequately. We like the underfloor downstairs is there anything we could do to try and get it working properly upstairs?

Thanks

FN

funnyname

I did a bit more checking on the underfloor upstairs and there's a concrete screed under the floorboards but there a gap of an inch and a half between then so I guess all the heat being output is heating the air between the gap and hence the poor performance and need to install the rads upstairs.

Is there any lightweight conductive material I could place between this gap to get the benefit of the underfloor?

antoinolachtnai

one thing you could do is just turn the valves so that the UFH in that part of the house runs for a very long period, maybe 24 hours. It will eventually heat. It will be slow but no heat will actually be lost. In general I do not think that there are any lightweight conductive materials, other than air, which you already have for free, and maybe aluminium, which you definitely don't want.

The real problem is that the heating elements are too far away from the floor, or maybe there aren't enough of them. A related problem is that those elements are probably not getting much hot water. This doesn't make the whole thing any less efficient, it just makes it an awful lot slower to heat.

Calahonda52

Just had quick read of this and would add that the various different circulation pumps can consume quite a bit: I have a system link with 5, asynchronous, pumps and they are all at 3 which means they are sucking 96 watts a pop, so say 100 by 5 is 500 watts when its on.

I only became aware of this elephant in the heating system recently so thought I would share it.
The electronic, synchronous, pumps are not cheap but......

HTH

OP: did u ever say if your HP is air to water or "wha?"

funnyname

Having issues with the (ground source) heat pump, mains power light in attached photo is flicking on and off and timer for calling the heat is off.

Had an issue last week with the timer not working but got it back on by turn off and on the two trip switches inside the unit. I tried that again tonight but no joy and thst that's when I noticed the red light.

The orange light for the gas is on as well so I just turned off the unit as the main fuse board. I will call a plumber in the morning but if anyone has any ideas that would be great.

funnyname

Anyone?

funnyname

Just to follow up on this, at the outset we had the following below but after upgrading the doors and windows and the insulation and airtightness of the house we now have an oil boiler left as the only heat source into the house. The heat pump died on us and we ditched the multi flue stove and oil range, the plan is to also ditch the thermal solar panels and use the space to max out with solar PV.

We want to replace the oil boiler with a new geothermal heat pump, just wondering if any one has any recommendations?

There are 5 heat sources

1. Solar tubes

2. Stove - Charnwood country 15b (output of 13 kW to water and 2.5 kW to room)

3. Oil range in the kitchen

4. Oil burner

5. Heat pump