Heat meter - Fun & games

FreeBear

michaels said:

FreeBear said:

Depending on model, you should get a current energy reading, a running total, flow rates, and temperatures (flow & return). Some will store data for the previous month that can be accessed via the display.

Once I get this T230 plumbed in and wired up, I'll post some of the data and maybe a graph. But with summer on the way, I don't anticipate running the heating until next winter.

Saw one just sold on ebay for 36.99 whereas all the ones for sale were closer to 100 - someone got a bargain....

Paid a bit less that that for mine

FreeBear

Don't you love these ebay bargains.... Had to spend as much again (plus a bit) for plumbing fittings and an interface board. Finding a suitable 1" fitting to plumb the meter in with, not so easy.

1" gas meter unions are not DN25/G1/1" BSP. Hot water cylinder unions, although the right thread, have a taper seat, so not compatible with the T230. Several Chinese suppliers on ebay and Aliexpress selling suitable fittings, but details are a little sketchy.. Fortunately, I had a lump of bronze to hand, so turned up a couple of tails to go with the cylinder unions. Also turned a thermal pocket so fit a branch tee for the hot side sensor.

And surprise, surprise, Postie delivered the mbus<->USB interface this morning. An excuse to take time out from other jobs to compile & test the software. All seems to be working, just need to drain the heating system to plumb it in.

michaels

I feel your pain having gone through that (and used the gas meter fittings).  Do you not just tape the temp sensors onto copper though?!

FreeBear

michaels said: Do you not just tape the temp sensors onto copper though?!

Much better if the temperature sensor is in the middle of the flow of water. See below -

FreeBear

Tested out the interface and meter using the utilities from libmbus - This blog has info on integrating with Home Assistant - https://the78mole.de/taking-your-m-bus-online-with-mqtt/

Being the glutton for punishment that I am, also looked at wmbusmeters - Documentation is rather lacking, but I eventually managed to figure out how to get it to work. If anyone needs a hand, feel free to ping me a message.

Sample output using wmbusmeters

{
    "media":"heat",
    "meter":"ultraheat",
    "name":"MyTempMeter",
    "id":"68803557",
    "flow_m3h":0,
    "flow_c":18.6,
    "heat_kwh":0,
    "power_kw":0,
    "return_c":18.5,
    "volume_m3":0,
    "fabrication_no":"68803557",
    "meter_datetime":"2024-03-27 15:45",
    "status":"TEMPORARY_ERROR",
    "timestamp":"2024-03-27T21:38:39Z",
    "device":"MAIN",
    "rssi_dbm":0
}

Meatballs

The other approach is to get these values from the HP itself. Daikin has open source projects with espaltherma and p1p2serial that can collect these from the serial busses on the device. I think there's similar with the Mitsubishi Ecodans etc

FreeBear

Meatballs said:

The other approach is to get these values from the HP itself. Daikin has open source projects with espaltherma and p1p2serial that can collect these from the serial busses on the device. I think there's similar with the Mitsubishi Ecodans etc

Would be OK if I had a heat pump. The goal of the current project is to determine how much heat I'm getting from my current gas boiler. Once I have that data, I'll be in a much better position to size a heat pump when the time comes.

In the meantime, the information I post here may be of interest to others heading down the same path.

michaels

FreeBear said:

Meatballs said:

The other approach is to get these values from the HP itself. Daikin has open source projects with espaltherma and p1p2serial that can collect these from the serial busses on the device. I think there's similar with the Mitsubishi Ecodans etc

Would be OK if I had a heat pump. The goal of the current project is to determine how much heat I'm getting from my current gas boiler. Once I have that data, I'll be in a much better position to size a heat pump when the time comes.

In the meantime, the information I post here may be of interest to others heading down the same path.

Do you have any other gas appliances - we only have the boiler so at least know how much energy is going in even if we don't know the efficiency.

Thinking of getting the landis and gyr 230 for our heath robinson ashp, too old for any sort of interface on the hp.  Can you rotate or disattach the screen part from the pipe part?  thanks

FreeBear

Just a combi boiler, no other gas appliances (aside from a blowtorch used with bottled gas). Whilst I know my annual gas consumption, that is for both heating and hot water. So not a simple task to work out how much is used for heating.

The display on the Landis+Gyr can be detached from the flow sensor and mounted up to 1.5m away. Unfortunately, I do not know the part number for the wall adapter plate or anyone that carries it in stock. So you might have to make one - It is not something that bothers me as I'll be using the mbus to take readings remotely.

michaels

FreeBear said:

Just a combi boiler, no other gas appliances (aside from a blowtorch used with bottled gas). Whilst I know my annual gas consumption, that is for both heating and hot water. So not a simple task to work out how much is used for heating.

The display on the Landis+Gyr can be detached from the flow sensor and mounted up to 1.5m away. Unfortunately, I do not know the part number for the wall adapter plate or anyone that carries it in stock. So you might have to make one - It is not something that bothers me as I'll be using the mbus to take readings remotely.

I use the summer no heating period as a proxy for hot water demand although obviously the incoming cold supply is a fair bit warmer in summer than winter.  Perhaps you could have 24 hours with just cold showers to get an idea of heating gas demand?!