Arduino powered servo arm for Hot Water service

Icarus · 26th February 2011, 1:19 AM

Hi all,

Thought I'd share a little project I've been working on for a bit.

As per the captions in the vid, sky-rocketing power bills and an impossibly difficult landlord drove me to this solution for switching off and on our hot water service.

Took several redesigns due to the leverage required to pull the switch to the off position and to make sure the arm travels far enough.

The 6v torch battery has lasted much longer than I expected. Still waiting for this quarters power bill to see how much of a difference it's made.

Cheers,
Ic.

gtc · 26th February 2011, 2:09 AM

$1,000 per quarter?!? And the bulk of that was down to the water heater?

Good grief! What brand is it?

Well that's quite a contraption, but I'm not sure how long that switch will last as I doubt it was designed for such frequent use.

Icarus · 26th February 2011, 9:08 AM

Quote:

Originally Posted by gtc

$1,000 per quarter?!? And the bulk of that was down to the water heater?

Good grief! What brand is it?

Well that's quite a contraption, but I'm not sure how long that switch will last as I doubt it was designed for such frequent use.

No idea what brand it is. That's actually part of the problem with getting it repaired. The unit itself is in the ceiling (with no manhole access) and we're on the top floor.

So the only way for a plumber/sparky to get access is to get onto the roof and remove some of the tiles. I've had 2 plumbers and 1 sparky flat out refuse to do it cos it's too difficult to access.

I have thought about the switchs longevity... As long as it last the 6 months until we move, I'll be happy

paulvk · 26th February 2011, 10:20 AM

The landlord owns the hot water service its his job to fix it! It may just be a leaking relief valve or worse still you could end up with hot water coming through the celing.

Icarus · 26th February 2011, 11:22 AM

Quote:

Originally Posted by paulvk

The landlord owns the hot water service its his job to fix it! It may just be a leaking relief valve or worse still you could end up with hot water coming through the celing.

Yep, I know, believe me. We have actually gotten to the stage where we know its faulty and cannot be repaired (its too old), but as I said above, we can't seem to find a plumber who will take on the task of replacing it.

This is a last resort, and something of an instant fix in terms of how the fault is affecting us (big power bills).

At one point I did look into my options in terms of going to VCAT but now that I know we'll be moving out within the next few months, and I've been fighting them for so long, I think I've just resigned to the idea that a permanent fix will never happen and soon it wont matter.

gtc · 26th February 2011, 12:31 PM

Quote:

Originally Posted by Icarus

No idea what brand it is. That's actually part of the problem with getting it repaired. The unit itself is in the ceiling (with no manhole access) and we're on the top floor.

So the only way for a plumber/sparky to get access is to get onto the roof and remove some of the tiles. I've had 2 plumbers and 1 sparky flat out refuse to do it cos it's too difficult to access.

I have thought about the switchs longevity... As long as it last the 6 months until we move, I'll be happy

Sounds like an old gravity feed heater. They are usually off-peak, too, in which case it would have a separate meter.

With huge bills like that, there really does seem to be a fault of some sort causing it to be on the heat cycle almost continuously.

And, yes, file that land"lord" under A for Arsehole.

Fishface · 26th February 2011, 1:05 PM

I'm a bit sceptical about the power bill being the result of a hot water system issue.

Sure it could have a leak but that will be visible somewhere.

It could have a faulty thermostat however this would be obvious as the water will be close to boiling point.

I'd expect that the HWS's share of the quarterly power bill would only be in the order of a couple of hundred dollars depending on how many people are having showers.

gtc · 26th February 2011, 1:13 PM

Quote:

Originally Posted by Fishface

It could have a faulty thermostat however this would be obvious as the water will be close to boiling point.

Faulty thermostat or jammed open pressure relief valve would usually cause the overflow to be running continuously, however given the in-roof installation that may be hard to see depending on how it is plumbed.

The last such tank I had (in the 60's) sat within a square copper "basin" with sides about 50mm high. That drained to an outlet that poked out of the nearest eave.

Icarus · 26th February 2011, 1:20 PM

Quote:

Originally Posted by Fishface

I'm a bit sceptical about the power bill being the result of a hot water system issue.

Sure it could have a leak but that will be visible somewhere.

It could have a faulty thermostat however this would be obvious as the water will be close to boiling point.

I'd expect that the HWS's share of the quarterly power bill would only be in the order of a couple of hundred dollars depending on how many people are having showers.

I'm convinced there is a fault with the thermostat as the water is scalding hot if the water heater is left it it's own devices. Also, there is a separate meter for the hot water service which spins 24/7 when the switch is left on.

I've tried the 'it's a safety hazard' approach with the landlod too, no dice.

gtc · 26th February 2011, 1:28 PM

Quote:

Originally Posted by Icarus

Also, there is a separate meter for the hot water service which spins 24/7 when the switch is left on.

If the meter spins 24/7 then it's not a typical off-peak installation, and the only time I've seen a separate meter for HWS is when it's a block of flats with a shared HWS and the owner divvies up the bill among the tenants.

However, I gather in your case the isolation switch is located in your separate tenancy?

paulvk · 26th February 2011, 1:36 PM

Now with this meter that spins 24/7 is there an off peak unit to switch it off and on?

Fishface · 26th February 2011, 1:38 PM

Quote:

Originally Posted by Icarus

Also, there is a separate meter for the hot water service which spins 24/7 when the switch is left on.

If there is a separate meter then it should be possible to calculate exactly how much energy the HWS is using.

If the meter is spinning 24/7 then the thermostat is faulty and I would be dragging the landlord of to VCAT over the issue.

gtc · 26th February 2011, 1:41 PM

Quote:

Originally Posted by paulvk

Now with this meter that spins 24/7 is there an off peak unit to switch it off and on?

There's a thought. I'm assuming ripple tone controlled off-peak, but if it's a time-of-day time switch perhaps that is faulty, or its override switch has been activated.

paulvk · 26th February 2011, 1:46 PM

A phone call to whoever owns the meters should get them out to inspect their gear and if its faulty how about a bit of a refund on your bill!

gtc · 26th February 2011, 1:46 PM

Can you give us a photo of the complete meter box?

26th February 2011, 1:19 AM	#1
Icarus Member Join Date: Jul 2001 Location: Melbourne Posts: 283	Arduino powered servo arm for Hot Water service Hi all, Thought I'd share a little project I've been working on for a bit. As per the captions in the vid, sky-rocketing power bills and an impossibly difficult landlord drove me to this solution for switching off and on our hot water service. Took several redesigns due to the leverage required to pull the switch to the off position and to make sure the arm travels far enough. The 6v torch battery has lasted much longer than I expected. Still waiting for this quarters power bill to see how much of a difference it's made. Cheers, Ic. Last edited by Icarus; 26th February 2011 at 9:57 AM.

26th February 2011, 10:20 AM	#4
paulvk Member Join Date: Mar 2010 Posts: 691	The landlord owns the hot water service its his job to fix it! It may just be a leaking relief valve or worse still you could end up with hot water coming through the celing. Last edited by paulvk; 26th February 2011 at 10:31 AM.

26th February 2011, 2:09 AM	#2
gtc Member Join Date: Jan 2011 Posts: 208	$1,000 per quarter?!? And the bulk of that was down to the water heater? Good grief! What brand is it? Well that's quite a contraption, but I'm not sure how long that switch will last as I doubt it was designed for such frequent use.

26th February 2011, 1:05 PM	#7
Fishface Member Join Date: Mar 2004 Location: Adelaide Posts: 1,593	I'm a bit sceptical about the power bill being the result of a hot water system issue. Sure it could have a leak but that will be visible somewhere. It could have a faulty thermostat however this would be obvious as the water will be close to boiling point. I'd expect that the HWS's share of the quarterly power bill would only be in the order of a couple of hundred dollars depending on how many people are having showers.

26th February 2011, 1:36 PM	#11
paulvk Member Join Date: Mar 2010 Posts: 691	Now with this meter that spins 24/7 is there an off peak unit to switch it off and on?

26th February 2011, 1:46 PM	#14
paulvk Member Join Date: Mar 2010 Posts: 691	A phone call to whoever owns the meters should get them out to inspect their gear and if its faulty how about a bit of a refund on your bill!