Sunamp failure - NOW FIXED!

[ToughButterCup]

Hmmm, .... only wearing a bathing costume all year round eh .... hmmm.  It'll be they wee midges that irritate. 

[SteamyTea]

6 minutes ago, Kelvin said:

theory is it’s the reason the sea water temperature is rising, all the women of a certain age going for a dook. 

Too true.

And they all park badly.

[Jeremy Harris]

59 minutes ago, Kelvin said:

The other day my wife asked what we’d do for showers if our system stopped working for some reason. I pointed to the newly plumbed in dog bath and electric shower. Has a handy shelf for sitting on and a door and step to get in. 😂 

 

Thinking about it, it'd be easy to buy a lower flow shower head, perhaps a bit like the ones used for electric showers, to use if we had to resort to the backup hot water system.  The shower head we use all the time has a flow rate of around 10.5 litres per minute (I only know this because an annoying building inspector wanted me to measure it, then insisted a flow reducer be fitted - removed as soon as the house was signed off . . . ).  I could probably find one with a much lower flow rate, rather than fit a flow reducer, simply because the flow reducer really reduced the force from the jets.  If I fitted, say, a head with an 8 litre/minute flow rate then we'd get close to 10 minutes of shower time, which is pretty close to normal daily use anyway.

 

This means that a 50 litre heater may well be all we need.  These Heatrae Sadia units look well enough made, stainless steel tank and immersion element, just a simple thermostat for control and all the connections at one end. 

[Gone West]

1 hour ago, Jeremy Harris said:

The question is whether 50 litres of hot water is OK as an emergency supply.

I think that looks like a good solution. I'm sure 50 litres of hot water is fine as an emergency supply, as 40 minutes recovery time is reasonable. Just read your last post. An aerating shower head would reduce the water use.

Edited January 20 by Gone West

[Kelvin]

8 minutes ago, ToughButterCup said:

Hmmm, .... only wearing a bathing costume all year round eh .... hmmm.  It'll be they wee midges that irritate. 

We don’t get so many midges our side of the hills even by the Lochs 

[Jeremy Harris]

I've ordered one of the 50L Heatrae Sadia horizontal water heaters, should be here at the end of the week.  Nice that it comes complete with all the bits needed to install it, PRedV, accumulator, tundish, built-in T/PRV etc, although the PRedV is redundant, as I already have a 3 bar one on the supply, plus our well pump cannot exceed about 4.5 bar anyway, given the depth of our well.   If anyone wants a 22mm PRedV they are welcome to it, as I already have one spare sat here.

 

Plan is to fix a doubled up bit of 19mm marine ply to the wall above the door, secured with loads of hefty screws into the studs behind the plasterboard.   Should be fine to then bolt the bracket to this, as the max weight when full is only a tad over 70kg.  Nice thing about this water heater is that it isn't smart, something of a rarity now.  Last thing I want for a standby, emergency hot water system, is something that is too damned clever for its own good.  Quite why anyone would ever feel the need to have a WiFi connected and controlled hot water heater is beyond me.  I just want something simple that will provide some hot water if things go awry.  Last thing I need is to be faffing around with an app in order to just have a shower.

 

 

[SteamyTea]

25 minutes ago, Jeremy Harris said:

Quite why anyone would ever feel the need to have a WiFi connected and controlled hot water heater is beyond me

It gives the impression that the customer has some control and can reduce their energy bills.

I blame the marketing departments.

 

(Metal Mickey was not at work today, so could not put the PCM under the lazer, hopefully he is in tomorrow)

[SteamyTea]

Saw the metal man earlier.

The first column is the element, second the percentage and third is the uncertainty.

 

 

[SteamyTea]

So do we know how the elements 30 (Zinc), 46 (Palladium), 48 (Cadmium) and 49 (Indium) all work together to control the phase changing?

[Onoff]

1 hour ago, SteamyTea said:

So do we know how the elements 30 (Zinc), 46 (Palladium), 48 (Cadmium) and 49 (Indium) all work together to control the phase changing?

 

I'm only guessing mind... 😂

 

https://chatgpt.com/share/67915a65-72e4-8006-81ed-e756c759a288

[Nickfromwales]

Maybe the extra heater is a little OTT? 
Would it not be ok to just use the Sunamp / Thermino, and IF it snuffs it again you just replace it with an UVC and be done with it?

 

That’s what a member on here did, eventually, when he realised he was seeing a SA repair & replacement engineer more often than he was seeing his wife…..

[Jeremy Harris]

45 minutes ago, Nickfromwales said:

Maybe the extra heater is a little OTT? 
Would it not be ok to just use the Sunamp / Thermino, and IF it snuffs it again you just replace it with an UVC and be done with it?

 

That’s what a member on here did, eventually, when he realised he was seeing a SA repair & replacement engineer more often than he was seeing his wife…..

 

 

It's really about having something to very quickly fall back on, Nick.  Not being able to shower for the best part of a week was a real nuisance when the SA failed, so having something relatively affordable that can just be switched on to give us some hot water  would be handy.  TBH if the SA does ever fail again then it will get replaced with a slimline UVC, but that's a lot of work, as it means relocating the hot and cold water distribution manifolds, relocating the UV water treatment and filter, and probably relocating the 100 litre pressure vessel, in order to get enough space.  It's doable, but probably two or three days work, on top of whatever delay there might be in getting someone in to do it.  That latter problem is one of the main reasons for the backup.  When I was ringing around the two people that were slightly interested made it clear they wouldn't be able to look at it for around 3 to 4 weeks.

 

This little 50 litre water heater isn't going to be the answer long term, but it is something that can be fitted quickly, with very little disruption (might have to have the water off for half an hour, tops) and can just sit there ready to be turned on and give us a couple of short showers a day (I hope!) if the worst happens.  It wouldn't interfere with the later installation of a slimline UVC in future, either, as it'll be high up on the wall above a door, so might be worth keeping if we did change to a UVC, if only to give us hot water if the immersion were to pop its clogs.

 

I'll freely admit to being a bit keen on having backups, but our experience so far has shown they are a blessing.  Our well pump failed about 5 years ago and having a backup pump, all wired and plumbed to a roll of MDPE, complete with a waterproof plug, was great.  Took about half an hour to haul the old pump out, lower the new one in, make off one 25mm MDPE union and plug the mains in and we were back up and running.  Needless to say there is now another spare pump hooked up and ready to go in the back of the garage!

 

We even (by accident) have backup heating.  The MVHR has an A2A heat pump, not very powerful, it draws about 400W, but when there was a power cut a couple of years ago it was great.  We didn't have enough spare battery power to run the main ASHP, but there was enough to run the small one in the MVHR and it did a surprisingly good job at keeping the house warm.

[SteamyTea]

7 hours ago, Onoff said:

I'm only guessing mind

Stable crystals then.

[Nickfromwales]

8 hours ago, Jeremy Harris said:

 

 

It's really about having something to very quickly fall back on, Nick.  Not being able to shower for the best part of a week was a real nuisance when the SA failed, so having something relatively affordable that can just be switched on to give us some hot water  would be handy.  TBH if the SA does ever fail again then it will get replaced with a slimline UVC, but that's a lot of work, as it means relocating the hot and cold water distribution manifolds, relocating the UV water treatment and filter, and probably relocating the 100 litre pressure vessel, in order to get enough space.  It's doable, but probably two or three days work, on top of whatever delay there might be in getting someone in to do it.  That latter problem is one of the main reasons for the backup.  When I was ringing around the two people that were slightly interested made it clear they wouldn't be able to look at it for around 3 to 4 weeks.

 

This little 50 litre water heater isn't going to be the answer long term, but it is something that can be fitted quickly, with very little disruption (might have to have the water off for half an hour, tops) and can just sit there ready to be turned on and give us a couple of short showers a day (I hope!) if the worst happens.  It wouldn't interfere with the later installation of a slimline UVC in future, either, as it'll be high up on the wall above a door, so might be worth keeping if we did change to a UVC, if only to give us hot water if the immersion were to pop its clogs.

 

10 - 4, rubber duck  

[Jeremy Harris]

The "emergency use only" 50 litre Heatrae Sadia arrived today.   Looks like it will be dead easy to install, as it's not heavy and will be an easy one-person lift up on to the wall above the services room door, especially as it has an easy to use "hook on" wall bracket.  Yesterday an "eco" shower head arrived from Victoria Plumb.  Pleasantly surprised by the performance of this, TBH.  It's rated at only 7 litres/minute but subjectively it feels a lot better than that.  My wife (highly critical of feeble showers) said she prefers it to the 10.5 litres/minute one we've been using for years.  Be interesting to see the energy the SA uses tonight to recharge, after a couple of showers with the "eco" shower head.  The last two nights it has taken near enough exactly the same time to charge, 1 hour 10 minutes, so about 3.3kWh*.

 

If the shower water usage has been reduced by around 30%, I'd expect the recharge time to reduce.  This small water heater holds water at its max temperature of 70°C (mixed down to about 50° for DHW and then mixed down again to ~38°C at the shower) to supply well over 80 litres, so more than enough for ten minutes of shower time with the new head.  I'm planning to us it as out primary hot water system for a day or two once it's installed and commissioned, mostly as an experiment.

 

Although such a low volume hot water system flies in the face of everything that is commonly stated as being essential for a reasonable level of convenience, I'm really keen to push the boundaries a bit and see just how little we could get away with, without too much inconvenience.  Although the unit I have has a standard 3kW immersion, the Eddi has the option of being able to set a lower power limit.  For those with battery systems this can be useful, as it can keep peak load within the inverter rating (ours is rated at 3.6kW max, in reality it manages a bit closer to 3.7kW).  One advantage we have is that our hot water often tops up overnight, during the off-peak slot, so the water heater won't have lost much heat between its thermostat having turned it off and the first shower (usually around 07:00).  This does mean the efficiency hit from storing hot water (which was the main reason for me opting for a SA back in 2016) won't be a major issue.

 

* That 3.3kWh is actually significantly lower than the charge that went in to our old SA UniQ 9kWh unit over the past few months.  I have no idea if this is in any way relevant to the failure, but, even though I don't have a lot of data they do seem to indicate that the new Thermino is using less energy.  Nothing else has changed, it's plumbed to the same pipes and run from the same Eddi, with no changes to any settings, yet it seems clear there is a very slight reduction in energy use, perhaps around 10%. 

 

 

 

[SteamyTea]

40 minutes ago, Jeremy Harris said:

I'm planning to us it as out primary hot water system for a day or two once it's installed and commissioned, mostly as an experiment.

I was going to suggest this as it would be interesting to see what the relative differences in heat loss and efficiency between the two system actually is.

 

I was going to experiment this year with just using the top heating element in my 200 lt cylinder, but decided to not use my two storage heaters instead.  May have to wait till summer for that experiment (I was forced into doing it once when the bottom element went and seem to remember that it worked OK with regards volume of water heated).