Gas water heaters

[alan_fincher]

All Morco Conventional flued water heaters now have Spilage Safety Devices as standard, as do all manufacturers these days

Can you explain that further.

 

I know they have oxygen depletion sensors, but is that the same thing as detecting any fumes getting where they should not be?

[The Commodore]

 

Getting picky again, there is no such thing as a 'conventional flued' appliance. Appliances are classed as 'flueless', 'open flued', or 'room sealed'.

 

Best to get the terminology right when offering gas advice...

 

 

MtB

 

 

Picky indeed! i'm old school and most Gas installers would know i was talking "opened flue"

[BlueStringPudding]

D61e Electronic ignition (battery), 61d piezo ignition.

 

And the D61B?

[alan_fincher]

And the D61B?

That is the "piezo", ("clicky/sparky") one surely.

 

Is there a D-61D???

[BlueStringPudding]

Now reading about them it says they raise the water temperature to 25 degrees above ambient. That doesn't sound very hot - what's the point of that?

Edited April 2, 2014 by BlueStringPudding

[MtB]

Can you explain that further.

 

I know they have oxygen depletion sensors, but is that the same thing as detecting any fumes getting where they should not be?

 

Do they?

 

The spillage detection device mentioned by The Commodore is a heat sensitive switch that detects hot flue gas spilling out into the cabin and disconnects the thermocouple circuit, shutting off the gas supply.

 

I've not seen a vitiation sensing device (posh name for it) (VSD) on a Morco yet...

 

 

MtB

[The Commodore]

Can you explain that further.

 

I know they have oxygen depletion sensors, but is that the same thing as detecting any fumes getting where they should not be?

 

On the Morco the Oxygen depletion device is the Spilage sensor, on other appliances it could be a type of pilot.

 

Sorry typo, it was D61b

[MtB]

 

 

Picky indeed! i'm old school and most Gas installers would know i was talking "opened flue"

 

?

 

 

 

MtB

[The Commodore]

 

Do they?

 

The spillage detection device mentioned by The Commodore is a heat sensitive switch that detects hot flue gas spilling out into the cabin and disconnects the thermocouple circuit, shutting off the gas supply.

 

I've not seen a vitiation sensing device (posh name for it) (VSD) on a Morco yet...

 

 

MtB

 

What is the effect of Oxigen depletion on a water heater ?

[MtB]

 

On the Morco the Oxygen depletion device is the Spilage sensor, on other appliances it could be a type of pilot.

 

Sorry typo, it was D61b

 

Bollox. C'mon, get a grip.

 

What is the effect of Oxigen depletion on a water heater ?

 

Same as any other appliance. Incomplete combustion.

 

MtB

[The Commodore]

 

Bollox. C'mon, get a grip.

 

Same as any other appliance. Incomplete combustion.

 

MtB

 

Which will cause spilage and the spilage sensor to operate.

 

 

I've finished with this pissing up the wall contest, take it away Boilerman.

[MoominPapa]

Now reading about them it says they raise the water temperature to 25 degrees above ambient. That doesn't sound very hot - what's the point of that?

 

That's at the rated flow-rate (ie 6l/min). 45 degrees is a perfectly acceptable shower temperature, so if your water tank is full of 20 degree water (in the summer) you get a brisk shower. In the winter, you have to turn the flow rate down (there's a control) to get the water hot enough. Ours is hot enough, even in the depths of winter, but the flow rate is lower.

 

MP.

[BlueStringPudding]

Erm... as I was asking!!!!!!!!!!!!!

 

Now reading about them it says they raise the water temperature to 25 degrees above ambient. That doesn't sound very hot - what's the point of that?

 

That's at the rated flow-rate (ie 6l/min). 45 degrees is a perfectly acceptable shower temperature, so if your water tank is full of 20 degree water (in the summer) you get a brisk shower. In the winter, you have to turn the flow rate down (there's a control) to get the water hot enough. Ours is hot enough, even in the depths of winter, but the flow rate is lower.

 

MP.

 

Oh I see - thank you for that.

Next question: how come they got banned by BSS and then reinstated again? Or is there only certain models of Morco (eg. ones built after a certain date) that are allowed to be fitted into a boat now?

[alan_fincher]

Next question: how come they got banned by BSS and then reinstated again? Or is there only certain models of Morco (eg. ones built after a certain date) that are allowed to be fitted into a boat now?

The BSS people realised they had been over-zealous, is one explanation!

 

Another is that the BSS people perhaps realised that there is little point in dictating that all instantaneous water heaters fitted to boats must be balanced flue if there are actually none manufactured that are suitable for boat use. (The unsuitability of the Morco F11 has been discussed on here many times - it might be practical for a houseboat, but by all accounts useless on a cruising narrow boat that needs to be able to pass under bridges).

 

The thing to remember is that for decades these things were the standard way of providing a source of hot water on just about every hire boat there ever was, (when most hire boats had air cooled Listers, you could not heat any domestic hot water from an engine, of course). If properly looked after they had an impeccable safety record, and it was daft introducing regulations that banned them as a new fit, in my view.

 

MP's post does however highlight one of the limitations. In winter, if you are starting off with much colder water at the input, then you either have to put up with cooler water coming out, or throttle back the flow to compensate, but then you get less water, albeit not as cool. This wasn't a consideration in hire boats in the summer, but is a bit of a drag in mid winter if the cold water in your tank isn't that much above freezing point.

[MoominPapa]

Next question: how come they got banned by BSS and then reinstated again? Or is there only certain models of Morco (eg. ones built after a certain date) that are allowed to be fitted into a boat now?

Call me a cynic, but it was probably something like the BSS decided that they should make boats as idiot proof as possible, and balanced-flue gas heaters are more idiot-proof than open-flued ones. Someone then pointed out that balanced-flue water heaters are totally impractical for boats, due to the requirements for power and large flue terminals. The BSS then decided that the trade-off between well-showered but very occasionally dead idiots, and never-dead but very smelly, unshowered idiots, was more in favour of well-showered variety.

 

 

MP.

[BlueStringPudding]

MP's post does however highlight one of the limitations. In winter, if you are starting off with much colder water at the input, then you either have to put up with cooler water coming out, or throttle back the flow to compensate, but then you get less water, albeit not as cool. This wasn't a consideration in hire boats in the summer, but is a bit of a drag in mid winter if the cold water in your tank isn't that much above freezing point.

 

It's a good point - a hot water heater that can only produce a dribble of hot water in winter isn't much use to me, really. I'm trying to imagine what a shower at 3 or 4litres per minute would be like... I have absolutely no idea of how to guage that

[Paul C]

 

It's a good point - a hot water heater that can only produce a dribble of hot water in winter isn't much use to me, really. I'm trying to imagine what a shower at 3 or 4litres per minute would be like... I have absolutely no idea of how to guage that

 

Well, your water pump will have a flowrate such as 7lpm, or 12lpm. Or you could turn the shower on and hold a jug under it with one hand and a stopwatch with the other....

[BlueStringPudding]

Next question, peeps. Do people with instantaneous water heaters also have calorifiers? If so, where in the circuit would the Morco go?

[MoominPapa]

Next question, peeps. Do people with instantaneous water heaters also have calorifiers? If so, where in the circuit would the Morco go?

Yes. Do not feed the Morco with water from the calorifier. You need a change-over valve that has two inputs, one from the Morco and one from the calorifier, and one output which goes to the taps. Manually select whichever is in use.

 

 

MP.

[BlueStringPudding]

Okay, trying to picture this. My water pump is at the front of the boat. The calorifier is at the back of the boat. The three sinks and shower are between the two. And my gas supply is at the front of the boat - which means ideally a Morco would also need to be at the front of the boat. Where would the changover valve go?

 

Although the forum search function on this subject has brought up some answers, I just see "inlet inlet inlet outlet outlet outlet" and I can't picture any of it. Anyone got a diagram or a simple explanation? I think reading other forum threads has just added to my confusion.

Edited April 2, 2014 by BlueStringPudding

[alan_fincher]

Okay, trying to picture this. My water pump is at the front of the boat. The calorifier is at the back of the boat. The three sinks and shower are between the two. And my gas supply is at the front of the boat - which means ideally a Morco would also need to be at the front of the boat. Where would the changover valve go?

This maybe not that easy to answer without looking at what you have in detail, but the "problem", if you have one, will be that currently your hot water taps and shower are fed by a hot water pipe from the calorifier at the back of the boat.

 

If you are not going to significantly re-plumb any of that, the point at which the two way valve to select hot water source needs to be somewhere along that pipe between the calorifier output, and the first tap or shower it serves.

 

If you want the Morco to be installed anywhere forward of the tap that is nearest towards the back, then ideally you will put the change-over valve as far forwards in the pipe I have just described as possible.

 

But even then you need to get hot water from the Morco to that change over valve as your alternate source of hot water. If you position the Morco right at the front of the boat, near your gas supply, then, when you are using the Morco, hot water will need to go all the way back to that valve, but then travel forwards again to whichever tap you have open. I'm guessing, depending on where your "furthest forward" hot tap is, that in a boat as long as yours, that could be a fairly long "round trip"? If it is you will therefore need to run the hot tap concerned for a rather long while before any "Morco-ised" water actually arrives at it, I think, which could be quite wasteful (or water, and potentially of gas, because when you turn the tap off again, you will have a long plastic pipe full of water you have just paid to heat, but which is now cooling down again.

 

Ideally you would have the Morco very close to the point at which you insert that selector valve, (ours is only a few feet away), but that means you will need to run gas back that far. (Finding a cold water supply to tap into shouldn't involve a long pipe run though, as there must already be a cold water feed right through the boat, if your fresh water tank is at the front, but the calorifier at the back).

 

I'm aware I have not said that well! If it's not clear, highlight the bit(s) that aren't, and I'll try to be less gobbledegook!

[BlueStringPudding]

Okay

So here's a diagram of my boat. Not sure if the coloured words underneath will line up and display correctly on everyone's computer:

calorifier hot water -->-------shower->sink 1-------------------------------------->sink 2---->sink 3

 

calorifier<-----------sink1 and loo<--------------------------------------sink 2<----sink 3<-------------------------------------------------------cold water

cooker<-----------------------------------------------------------------------gas

 

Alan, I think you've described my boat's set up correctly. And it's 65ft long so any extension of either plumbing or gas pipes would be long.

 

If I'm understanding you right, the changover valve would need to be between the calorifier and the shower. That's tricky already as there is no exposed hot water pipework till you get under the sinks (it's all boxed in behind the walls). And that would also leave 20-25ft of water pipe between the Morco and the shower, assuming the Morco was positioned above sink 2 (which is as far back as the gas pipe reaches) Is that what you're suggesting would be required if I didn't want to extend the gas pipes? (And I don't, incidentally )

 

Currently when using the shower with hot water from the calorifier, there is about 14ft of water pipe to run off cold before the hot comes through.

Edited April 2, 2014 by BlueStringPudding

[alan_fincher]

Neither your bow or stern profile will be doing anything for a smooth passage through the water - does MS cause a lot of wash?

 

Seriously though.....

 

I think if you are not seriously going to re-plumb what you have already, that new "selector" valve needs to be in that back room, because it will need to be "behind", that bathroom.

 

If that's your kitchen sink well towards the front, then if you have the Morco at the front, when you open a tap at that sink when in "Morco mode", you have got to wait for hot water to travel right back to that new valve, (through an all new pipe), then forward again through existing pipework to the sink.

 

"Water wise" it will be better to put the Morco aft of the bathroom, near the valve, but that means getting a gas supply through to that point, (and which will probably need to be a 1/2" pipe, to give ample flow rate without pressure drop). Could be a lot of upheaval?

 

There is a less swish solution, involving less changes, but more prone to user error, which I think, will work....

 

1) Keep all the back of the boat as is, other than introducing a simple lever valve into the hot feed pipe from the calorifier, anywhere "behind" that bathroom.

 

2) Put Morco at front of boat, with minimal gas piping required.

 

3) Connect Morco hot feed to your existing hot pipes, but at the front end of the boat, near what I assume to be the kitchen sink.

 

4) Also place a simple lever ball valve in that hot feed from Morco to existing hot supply to taps.

 

You now have to correctly use both those ball lever valves to effect a switch over from one hot water source to the other - basically whenever you open one, you have to go and close the other. If you try and have both open at the same time, I wouldn't like to predict......

 

Unless someone can see why that will not work, I think that could limit all your changes (other than introducing one valve) to the front of the boat, with no need for long extra pipe runs for gas or hot water.

 

But it's late - maybe there is some "gotcha" with this "fudged" approached that I have missed?

 

 

Edited April 2, 2014 by alan_fincher

[cereal tiller]

Neither your bow or stern profile will be doing anything for a smooth passage through the water - does MS cause a lot of wash?

 

Seriously though.....

 

I think if you are not seriously going to re-plumb what you have already, that new "selector" valve needs to be in that back room, because it will need to be "behind", that bathroom.

 

If that's your kitchen sink well towards the front, then if you have the Morco at the front, when you open a tap at that sink when in "Morco mode", you have got to wait for hot water to travel right back to that new valve, (through an all new pipe), then forward again through existing pipework to the sink.

 

"Water wise" it will be better to put the Morco aft of the bathroom, near the valve, but that means getting a gas supply through to that point, (and which will probably need to be a 1/2" pipe, to give ample flow rate without pressure drop). Could be a lot of upheaval?

 

There is a less swish solution, involving less changes, but more prone to user error, which I think, will work....

 

1) Keep all the back of the boat as is, other than introducing a simple lever valve into the hot feed pipe from the calorifier, anywhere "behind" that bathroom.

 

2) Put Morco at front of boat, with minimal gas piping required.

 

3) Connect Morco hot feed to your existing hot pipes, but at the front end of the boat, near what I assume to be the kitchen sink.

 

4) Also place a simple lever ball valve in that hot feed from Morco to existing hot supply to taps.

 

You now have to correctly use both those ball lever valves to effect a switch over from one hot water source to the other - basically whenever you open one, you have to go and close the other. If you try and have both open at the same time, I wouldn't like to predict......

 

Unless someone can see why that will not work, I think that could limit all your changes (other than introducing one valve) to the front of the boat, with no need for long extra pipe runs for gas or hot water.

 

But it's late - maybe there is some "gotcha" with this "fudged" approached that I have missed?

 

 

3 Way valve is essential,the hot water can only be drawn from water heater OR Calorifier NEVER both

Edited April 2, 2014 by cereal tiller

[BlueStringPudding]

Thanks Alan - I also think you might have posted before I added the notes which may have made it a bit trickier.

 

it's starting to sound way too complicated an upheaval of the boat fit out to be worth considering.

Neither your bow or stern profile will be doing anything for a smooth passage through the water - does MS cause a lot of wash?

 

- I drew it on a "design your room" type app on my old ipad a couple of years ago. It couldn't do curved lines. But did have a lovely selection of oval shaped rugs, sinks and toilets

 

At the moment I don't waste the 14ft pipe of cold water before the hot runs through, because I use it to wash my hair before I get into the shower. I don't mind that, and by time I've finished rinsing my hair the hot water is coming through and it's piping hot shower time. 20-25ft cold water though... ?

Edited April 2, 2014 by BlueStringPudding