@johnmo

https://www.nhs.uk/conditions/legionnaires-disease/

Regards, Toodles.

and also:

https://www.health.ny.gov/diseases/communicable/legionellosis/fact_sheet.htm#:~:text=An%20outbreak%20of%20this%20disease,illness%20was%20changed%20to%20Legionellosis.

Regards, Toodles.

And

https://www.heatgeek.com/hot-water-temperature-scalding-and-legionella/

@derek-m @jamesPa @johnmo 

A simple Thermostat?

Can anyone recommend a no-nonsense Thermostat?

My second problem is my Honeywell Home Thermostat.

My Honeywell home is still producing an apparent  cycle time of ~20 minutes:

Notice the RUN Time is also fixed at ~7 minutes:

Can anyone recommend a no-nonsense Thermostat that does NOT switch itself ON and OFF every 5, 10 or 20 minutes?

@johnmo There again, before the ASHP was fitted last year, we had had a vented cylinder fed from a coldwaterb tank in the loft complete. with dust, spider’s webs and goodness knows what else. At one time some years ago. I drained and cleaned out this tank. I’m rather glad we are on an unvented system now! Toodles.

Posted by: @iantelescope

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Can anyone recommend a no-nonsense Thermostat?

 

My second problem is my Honeywell Home Thermostat.

My Honeywell home is still producing an apparent  cycle time of ~20 minutes:

The problem could be flow temperature to high. The thermostat should really be seen as a means to stop over temperature from solar gain etc) not to control house temperature. If you use it to control temperature by default you are actually flowing too hot. Therefore getting a lower CoP than you should.

For thermostats I like a Computherm Q20RF. Available from Amazon. They have an adjustable hysterisis from 0.1 to 1 in 0.1 intervals. So if set to 20, and 1 deg hysterisis, would let room drop to 19 degs before switching on the heat pump and it would stay in until 21 deg. Set to 0.1 is good for thick screed UFH to stop temperature overshoot.

@derek-m 

Shorting HEX ports !

EAC are located in Ahmadabad , India .

 EAC manufacture major components for power stations.

From previous experience, nearly two years ago, I can  find nothing about EAC Heat Ex changers.

I also doubt that fitting the Heat ex changer with the inputs and outputs interchanged  will affect efficiency.

I will have to remove the Heat Ex changer myself, no one will  help , or accept responsibility.

I will simply short out the top two , and bottom two , heat ex changer ports, then removing the second motor .

Posted by: @iantelescope

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My Heat Ex changer has been configured such that :

K1 = Secondary Cold Input

K4 = Secondary Hot Output

K3 = Primary Hot water Input

K2 = Primary Cold Water Return

The install isn't following normal conventions, but from a heat transfer perspective it shouldn't make to much difference. As long as at one end the flows are the coldest and the other end they are the hottest.

Both flows are forced circulation by pumps so it makes little difference which orientation the heat exchanger has.

The internals of the heat exchanger are design to promote turbulent flow, so you could have more or less turbulence as the flows are effectively the wrong way round on each side of the exchanger.

If you are able to get the cylinder hot enough without immersion, leave as is.

@johnmo 

Many thanks for the info on the Computherm .....I was looking for just such a Thermostat with hysteresis.

My flow temperature is set by the weather compensation, using the Thermostat timer to adjust the Room and therefore  Flow temperature to store energy in my pipes and Buffer tank during the Low tariff periods set by Octopus "Cosy".

@johnmo 

Again, many thanks @johhnmo .

I will leave the Heat Ex changer until I can get a good plumber to help.

I have long wanted to remove the HEX, Buffer tank, Second motor , third expansion tank and the excessive Hot water Cylinder but have little confidence, in myself, or this industry.

@iantelescope

Do you have Glycol in the primary circuit?

@derek-m 

Glycol in primary circuit ?

No , I do not have glycol in either primary or secondary circuit .

The primary circuit appears to be filled with "ink".!