Hot water immersion through Eddi - longer immersion element not responding

John.G

https://www.boards.ie/discussion/comment/123771838#Comment_123771838

Any idea yet of the max temperature with the Willis running at the full 3.0kW?.

dingding

Hi John,

Ill try to get to it in the next day or so and take some temp readings.

Cheers.

M

dingding

@John.G

Left it running for 20 minutes on boost (full power) after drawing off some water.

It heated to 85 C at the top where the pipe was connected and the pipe at the top of the tank was a similar temp.

Could not get any other readings because of the insulation.

dingding

@manatoo Interesting that the electricity is cheaper to heat than the gas.

I have a zoned system, in almost 30 years. The valve on the water cylinder is passing water through. Enough to heat the cylinder, so I am heating with the kerosene more because I have to.

In any event I used Tado X valves and a couple of their room stats to control all the rads, I have about 20, while there were teething problems at first with connectivity, I worked with their technical team to resolve it, I think I was one of the test cases as my previous background was data comms. I was working with one of their senior technicians, had a couple of zoom calls, tried different wifi configs etc and now it doesn't miss a beat.

Last year I had the Tado in for about haalf the year and I topped up my tank by 800 Litres. So I would expect it to be less this year, as I have the Tado X system for the entire year, and it is reliable.

While it cost a couple of grand to put in the Tado stuff, I purchased it all on various deals on amazon and one item from them via a mate in the netherlands, I would recon the pay back time would be a couple of years. I would have been using twice the amount of oil in the past.

I also got the attic insulated and pumped beads in the wall.

I think as others have comented the big saving is to heat the water as much as possible on the night rate for 12C and export all the excess for 20C.

If they tax it in the budget, it will then make more sense to self use all the solar, but this is not in the interest of the grid, and its decarbonisation as solar is not available during peak times, it is effectively heating water that can use excess green (wind) power at night.

manatoo

https://www.boards.ie/discussion/comment/123784652#Comment_123784652

@dingding both interesting and disappointing. Especially since the old boiler cost barely anything more to heat the cylinder than the new boiler does, at a cost of 4 grand.

I got external wall insulation, complete attic insulation and all new windows and external doors as part of the upgrade. The only thing left as it was is the floors.

Of course without telling me (granted I didn't ask but you'd still think they'd have consulted with me given they are the "experts"), when they installed the zones I only got heating/rads. I thought they would also do upstairs/downstairs. So now I have to have all upstairs rads on with the downstairs ones regardless of the temp difference. They did put "dumb" trvs on all rads but honestly they just don't work at all in my experience. It's nigh on impossible to set them to a defined temperature and have them click in and out. There's too many variables.

I was thinking the solution was to install smart trvs on the upstairs rads, thus giving me that "zone" but I'm told the pin in the cylinder under the trvs they installed is not compatible with any other trv and I wouldn't be knowledgeable enough to drain the system to replace the pins/cylinders. It would cost me at least a grand to buy the smart trvs and hub and labour time and I've spent enough on the place at this stage. Will just have to live with what I have

dingding

I had a 28mm valve, very unusual and there was a Tado adapter for it.

They have a good range of adapters. The Tado and there is similar allows you to independently control each room. And it also monitors humidity and temperature so you can heat a room intermittently if there is a mould risk.

My boiler is relatively new. About 4 years and it was a grant condensing boiler.

I’ll take some screen shots of the Tado system later. You can connected it to rooms in google home and control the temp with hey google.

I would recommend doing it in stages but plan to do the entire house.

you could order a valve on Amazon. Try to install, if not compatible just return

dingding

some screen shots from the Tado app.

Each room can be independently controlled and monitored. The batteries are a rechargeable usbc in each valve and the room stats have standard, I think AA batteries.

dingding

i found with the previous TRVs I got them in homebase and they weren't consistanct. There were manufacturing differences in the plastic heads and they all gave different temp readings for the same rad.

So apart from a handy way to turn the radiator on or off, they weren't much use at all.

The Smart ones are a completly differnt kettle of fish, and they callibrate themselves when you install them so that they all work the same regardless of the water valve.

John.G

https://www.boards.ie/discussion/comment/123784603#Comment_123784603

That 85C temp is what I would have expected, another poster on here, @tnegun, used 3/4" pipework throughout and installed a pipestat set to 75C, don't know if the temperature would still climb to the 80s if no pipestat installed, he also had to set the Willis stat down around 40C which he reckons will only operate at a willis outlet temperature of ~ 85C, as stated previously, its amazing how virtually nobody of literally thousands of willis installations or similar has mentioned these very hot temperatures.

dingding

Yes. When it is running you can hear a noise like boiling water or steam occasionally running through the system. In my case it leaves the hot water potentially dangerously hot at the tap.

In order to get the electronic pumped shower to work correctly I had to install a thermostatic blender valve on the hot inlet set about 60 degrees.

On mine it looks like the Willis thermostat never trips, probably only doing so when the tank has filled with water and there was no place to go.

They really need some sort of thermostat or temperature feedback from the tank to operate efficiently.

And probably blender valves or thermostatic taps on all the sinks and showers.

John.G

Circulating Force in Gravity System Extract Rev0.xlsx

Its nothing short of a miracle IMO that these type of heaters work at all, mainly because the circulating height is so small, if a 1M circulating height is assumed then the circulating force with inlet/outlet temps of 15C/55C is only 0.55 inches and still only 1.22 inches with inlet/outlet temps of 15C/85C, if my calcs are correct.