Instantaneous Water heaters

[bag 'o' bones]

I've been staying up in cumbria for the last few days for our annual archaeology dig.

 

Anyway the caravan had a Morco fitted, first time i've ever seen one up close to be honest as we don't have a water heater fitted on the boat.

 

Just as a matter of interest how much gas does the pilot light get through when just ticking over? Seems a very wastefull method of igniting the burner

[MtB]

I've been staying up in cumbria for the last few days for our annual archaeology dig.

 

Anyway the caravan had a Morco fitted, first time i've ever seen one up close to be honest as we don't have a water heater fitted on the boat.

 

Just as a matter of interest how much gas does the pilot light get through when just ticking over? Seems a very wastefull method of igniting the burner

 

 

Well if I forget to turn the gas off on my boat a 3.9kg bottle will usually be empty after a week or two so the answer seems to be 'quite a lot'

 

The main reasons for having a permanent pilot light instead of electronic ignition are speed of lighting and low cost of manufacture. Adding electronic ignition would roughly double the manufacturing cost I reckon, and would require a power supply too which they currently do not need.

 

When you turn a tap ON with a permanent pilot water heater you get more or less instant ignition which means minimum delay in hot water arriving at the tap, which in turn means less cold water wasted and boaters/caravanners don't want to run 10 litres of cold water down the drain while electronic ignition fires up and goes through flame-sensing etc before lighting the main burners. All in all I predict you would HATE one without permanent pilot!

 

Keep the pilot turned OFF generally and light it when you need hot water. That's the best way to use a Morco in my opinion.

 

Cheers, Mike

[DaveP]

I've been staying up in cumbria for the last few days for our annual archaeology dig.

 

Anyway the caravan had a Morco fitted, first time i've ever seen one up close to be honest as we don't have a water heater fitted on the boat.

 

Just as a matter of interest how much gas does the pilot light get through when just ticking over? Seems a very wastefull method of igniting the burner

 

When I first got my boat, I left the pilot on continuously - a 13kg bottle would last about a month. Moving to only lighting the pilot when water is required extended the bottle life to nearly two months!

[DeanS]

We have one. We also only ignite it when we use it...for showering or dishwashing....instant hot water.

[Laurie Booth]

Total waste of money. I have had 2 go wrong on me and C of C problems. Now use the hot water from the engine.

[MtB]

Total waste of money. I have had 2 go wrong on me and C of C problems. Now use the hot water from the engine.

 

You don't have raw water cooling then do you....?

 

:-)

 

Mike

 

P.S. Rinnai water heaters are a fiendishly unreliable, a pain in the butt and best worth avoiding in my experience (as a LPG boat gas bod) but Morco's are fine. Alan may disagree!

[ridders]

imo these are all pretty much the same, except the extinct paloma which was nice with the extra pilot burner to pull the gas through quickly.

best one has to be the little bosch "w" series, they have electronic ignition and flame sense from a battery -so when you aren't using it there's no pilot light!

none of them are room sealed though, so not the safest option

[Laurie Booth]

You don't have raw water cooling then do you....?

 

:-)

 

Mike

 

P.S. Rinnai water heaters are a fiendishly unreliable, a pain in the butt and best worth avoiding in my experience (as a LPG boat gas bod) but Morco's are fine. Alan may disagree!

Nope

[alan_fincher]

........ but Morco's are fine. Alan may disagree!

If that's me, Alan, then, no, I don't.

 

I think Morcos are fairly OK, though I now only use ours if we are not boating anywhere, so the water doesn't get heated by the engine - which is fairly rare. (The Calorifier was only added to our boat after we had had it some years, but is now obviously the prefered option, if only not to be paying for gas if we don't need to).

 

I would agree that the pilots consume a fair amount of gas, so, if you can, better to light only when hot water is needed.

 

I don't think the fact they are open flued devices is very important, safety-wise. hey have a good track record, if properly installed, and, despite the lack of reliable data, I doubt they have caused too many deaths, unless abused.

 

I have no experience of Palomas or Rinnais to compare them to Morcos.

[Mick_B]

On a similar vein... I have a Morco that works a dream in the spring, summer and autumn but come wit winter months (possible six a year lately) it only gets the water to what I would call tepid. Have checked and do not have a carbon build up and flame is 90% blue.

 

Q. Is it ready for the skip?

[Daftmare]

http://www.morcoproducts.co.uk/stock-5-3/Water_Heaters/F11E.html

 

Morco do a room sealed product now, which they advertise as suitable for narrowboats. Pricy though!

 

Jo.

Edited June 29, 2011 by Daftmare

[alan_fincher]

On a similar vein... I have a Morco that works a dream in the spring, summer and autumn but come wit winter months (possible six a year lately) it only gets the water to what I would call tepid. Have checked and do not have a carbon build up and flame is 90% blue.

 

Q. Is it ready for the skip?

Long version(!)

 

This is fairly normal - a new one will do the same.......

 

The reason is that basically because it has a maximum rate at which it can burn gas, if you look at the spec, I think at a full flow of 6 litres per minute, it is designed to increase the temperature of the water by 25 degrees, between it's "in" side and it's "out" side.

 

If the water in your cold water tank in summer is at (say) 15 degrees, then with luck at full flow the Morco can heat it to 15 + 25 = a very comfortable 40 degrees.

 

But if the water in your tank is at (say) only 5 degrees, then the Morco can't do better than 5 + 25 = 30 degrees, which, being less than body temp, feels really chilly, (particularly if the air in your boat is colder to).

 

I see this as the major limitation of these units for year round use. You can get hotter water out, of course, but only by throttling back the flow rate to well below the maximum of 6 litres per hour.

 

Short Version .

 

If you replace your Morco with a new one, you may not see any improvement in Winter.

 

(With one caveat - the older Morco D-51 doesn't heat the water as much as the later D-61 - changing a D-51 to a D-61 will produce a small improvement for the same flow rate).

 

http://www.morcoproducts.co.uk/stock-5-3/Water_Heaters/F11E.html

 

Morco do a room sealed product now, which they advertise as suitable for narrowboats. Pricy though!

 

Jo.

 

Much discussed in the past.

 

They need a massive external balanced flue, which can't be shortened, so really can only be used on a canal boat if you don't take it anywhere, as otherwise it will project too far through the roof for low bridges.

 

Also need a permanent 240 volt supply.

 

Chandlers have admitted on here to stocking one, but never being able to sell it, and it's for a good reason.

 

I have yet to hear of a satisfactory installation of that in a cruising narrow boat, but there have certainly been reports on here of unsatisfactory installations.

 

It was, I believe, the uselessness of the balanced flue product in the canal environment that caused the BSS office to relax the restrictions on fitting the far more practical open-flued models.

 

In short - don't buy one!

[Mick_B]

Thanx Alan.. You have basically confirmed what I thought myself but just in case asked in case others found it to be differant. This year I I had ice in my water tank so 5 degrees is a little optomistic..

[MtB]

imo these are all pretty much the same,

I disagree. The Rinnai is a FAR worse product than the others. I fitted a Rinnai in my own boat a couple of years ago and it's behaviour is degrading just like all the repair calls I've had for them. It requires an ever higher water flow rate through it to make the burner light as the months and years go by. This is usually caused by a perished diaphragm and Rinnai tech support will tell you the same if you call them for advice. They then tell you the 75p neoprene diaphragm is not available as a spare part and you have to buy a whole 'refurbishment kit' which includes the diaphragm but costs £50.

 

The rub is that when you carry out the 'refurbishment' by fitting the kit, it makes no difference. The symptoms continue. Rinnai tech then say they don't know what else could be wrong. Fat lot of help that is! By this stage I will have used up enough time to have paid for a new one so these days I decline to repair Rinnais, advising any paying customer to fit a new one immediately instead. If you are doing your own repairs then it is a different matter, but so far I have failed to fix even my own Rinnai. Maybe that proves my own incompetence but I'll eventually get to the bottom of it though, and when I do, I'll let Rinnai tech know the solution

 

except the extinct paloma which was nice with the extra pilot burner to pull the gas through quickly.

 

Careful now. There are at least two different Paloma models out there, completely different. So be careful of assuming any given Paloma is the 'good one'. And by the way, the Rinnai has the same 'extrafast' pilot burner fitted to the earlier 'two control knob' Paloma.

 

best one has to be the little bosch "w" series, they have electronic ignition and flame sense from a battery -so when you aren't using it there's no pilot light!

none of them are room sealed though, so not the safest option

 

I've often heard of the Bosch W but never encountered one. Worcester Bosch deny ever making it if you call them for technical info. Does anyone have an instruction manual for the Bosch W please?

 

Cheers, MIke

[ridders]

I've often heard of the Bosch W but never encountered one. Worcester Bosch deny ever making it if you call them for technical info. Does anyone have an instruction manual for the Bosch W please?

 

http://www.worcester-bosch.co.uk/cache/file/240/installation--servicing-and-user-instructions-for-w-135--275--350-and-400.pdf

[MoominPapa]

from the PDF ridders linked to:

 

whenever a hot water outlet is opened,

automatic ignition will take place by lighting the pilot burner

first, and the main burner about four seconds later.

 

Sounds like quite a water-waster.

 

MP.

[Ex- Member]

from the PDF ridders linked to:

 

 

 

Sounds like quite a water-waster.

 

MP.

 

 

 

Not sure why that would waste water, probably initiates ignition by pressure sensor so as soon as water moves the unit ignites. Better than my calorifier which pumps over a litre of water through tap before we get hot water. I quite like these gas heaters but don't think i can fit one now as our fit out is almost complete and where i want the unit is 55f/t from the gas locker LOL

[MoominPapa]

Not sure why that would waste water, probably initiates ignition by pressure sensor so as soon as water moves the unit ignites. Better than my calorifier which pumps over a litre of water through tap before we get hot water.

Just the delay between water flow and main-burner ignition. Our Morco fires in less than a second and the pipes are short so that the water arrives at the tap a second after that. With this you've much more cold water to dump before you get hot through.

 

MP.

[Chertsey]

http://www.morcoproducts.co.uk/stock-5-3/Water_Heaters/F11E.html

 

Morco do a room sealed product now, which they advertise as suitable for narrowboats. Pricy though!

 

Jo.

Does it still require a 240v supply (as I recall an earlier one did)?

Even the BSS have accepted that non room sealed water heaters are safe.

 

Ah, I see Alan's already said it.

 

Mike, do you have any experience of the Vaillant? There's one fitted on Tarporley and it looks like a good solid piece of kit. I had one of their domestic boilers many years ago and it was excellent. But not cheap I would imagine and thus probably not that common.

Edited June 29, 2011 by Chertsey

[FadeToScarlet]

Total waste of money. I have had 2 go wrong on me and C of C problems. Now use the hot water from the engine.

 

And, in true CanalWorld style, I have the diametrically opposite experience. Our Morco has worked faultlessly apart from once requiring the thermocouple to be moved into the pilot light flame.

 

Far far less hastle and the most instant method of heating than any other method of boat water heating, I feel.

[ridders]

mike did you put the new water venturi and spring into yours, was there any build up of scale in the ports?

and have you seen the service manual on rinnai uk - there's only an installation instruction book for the 58, but the service book for the 56 has some good drawings

http://www.rinnaiuk.com/rinn/assets/templates/shop/Downloads/4_Water_Heater_Downloads_PDFs/16_Rinnai_REU_56es_Service_Manual.pdf

i'm interested because i've never repaired a rinnai, i've worked on all the other heaters mentioned, and always meant to change burst palomas for the rinnai model, but our local parts center always has morco d61's in stock !

Edited June 29, 2011 by ridders

[MichaelQ]

And in my turn I disagree with Mike the Boilerman about the Rinnai heater.

 

I WAS having troubles until I discovered a cure - the trouble was that heating became erratic, and at best slow and limited.

 

Seems that the water pipes inside the heat exchange unit are very narrow and scale up easily: that makes the flow slow, which in turn makes the gas cut off.

 

So I descale it every two years or so.

 

Disconnect the heater, take it outside and stand it upside down. Be careful not to lose the mesh filter in the inlet opening. Pour a little hot (boiling) water in to the water inlet (beware - not the gas inlet!!); then a measure of kettle de-scaler (I used Kilrock) and slowly top up with more hot water. Watch it bubble and sizzle. After a while, turn upside down and let all the liquid come out - it was very very green.

 

Flush (I used gentle pressure from a hose for a few minutes) and it's ready to re-install.

 

Both controls moved much more easily afterwards, and the heater works fine, just as new.

 

Thanks to Uxbridge Boat Centre who suggested this rather than sell me a new heater.

 

MichaelQ

 

 

 

I disagree. The Rinnai is a FAR worse product than the others. I fitted a Rinnai in my own boat a couple of years ago and it's behaviour is degrading just like all the repair calls I've had for them. It requires an ever higher water flow rate through it to make the burner light as the months and years go by. This is usually caused by a perished diaphragm and Rinnai tech support will tell you the same if you call them for advice. They then tell you the 75p neoprene diaphragm is not available as a spare part and you have to buy a whole 'refurbishment kit' which includes the diaphragm but costs £50.

 

The rub is that when you carry out the 'refurbishment' by fitting the kit, it makes no difference. The symptoms continue. Rinnai tech then say they don't know what else could be wrong. Fat lot of help that is! By this stage I will have used up enough time to have paid for a new one so these days I decline to repair Rinnais, advising any paying customer to fit a new one immediately instead. If you are doing your own repairs then it is a different matter, but so far I have failed to fix even my own Rinnai. Maybe that proves my own incompetence but I'll eventually get to the bottom of it though, and when I do, I'll let Rinnai tech know the solution

 

 

 

Careful now. There are at least two different Paloma models out there, completely different. So be careful of assuming any given Paloma is the 'good one'. And by the way, the Rinnai has the same 'extrafast' pilot burner fitted to the earlier 'two control knob' Paloma.

 

 

 

I've often heard of the Bosch W but never encountered one. Worcester Bosch deny ever making it if you call them for technical info. Does anyone have an instruction manual for the Bosch W please?

 

Cheers, MIke

[mrsmelly]

We have one. We also only ignite it when we use it...for showering or dishwashing....instant hot water.

 

I had a rinnai on an old boat years ago that was fab, had the boat five years and it was no problem ( Liveaboard ) The boat I am in the process of buying is great it has four methods of water heating to cover any eventuality. It has morco gas heater, webasto diesel heater, electric immersion and water from the engine heatin............. Flippin marvelous.....

[NBMike]

 

 

I've often heard of the Bosch W but never encountered one. Worcester Bosch deny ever making it if you call them for technical info. Does anyone have an instruction manual for the Bosch W please?

 

Cheers, MIke

 

I was working at a house where a brand new Bosch kitchen was fitted 14 years ago. My clients had recently contacted Bosch to try to get a replacement door only to be told that Bosch have never ever made kitchens. I was there at the time of install and saw it being unpacked so can verify that they indeed did!

PS another vote for two knob Palomas, zero for Rinnai

 

Mike (NB)

[MtB]

And in my turn I disagree with Mike the Boilerman about the Rinnai heater.

 

I WAS having troubles until I discovered a cure - the trouble was that heating became erratic, and at best slow and limited.

 

Seems that the water pipes inside the heat exchange unit are very narrow and scale up easily: that makes the flow slow, which in turn makes the gas cut off.

 

So I descale it every two years or so.

 

Disconnect the heater, take it outside and stand it upside down. Be careful not to lose the mesh filter in the inlet opening. Pour a little hot (boiling) water in to the water inlet (beware - not the gas inlet!!); then a measure of kettle de-scaler (I used Kilrock) and slowly top up with more hot water. Watch it bubble and sizzle. After a while, turn upside down and let all the liquid come out - it was very very green.

 

Flush (I used gentle pressure from a hose for a few minutes) and it's ready to re-install.

 

Both controls moved much more easily afterwards, and the heater works fine, just as new.

 

Thanks to Uxbridge Boat Centre who suggested this rather than sell me a new heater.

 

MichaelQ

 

 

Hello MichaelQ,

 

New member I see, welcome to the forum!

 

Interesting idea to descale regularly, particularly as you say it frees up the right hand control knob which grows stiffer by the week on mine despite being only three years old and getting minimal use. My Rinnai is already causing me problems, refusing to run the shower reliably (when it worked perfectly when new), which is partly why I hold them in such low regard when I the Paloma I had which served us well for three years of continuous use daily when we lived on the boat.

 

Having owned all three models of water heater I agree with NBmike that the two knob Paloma is the best, closely followed by the Morco with the Rinnai trailing a long way behind as a terrible third choice and best avoided. I have a scrap Rinnai in my porch at the moment (the one in which I installed the nose-bleedingly expensive repair kit which made no difference) so perhaps I'll descale that using my professional descaling pump and use it to replace the one in my boat, for a test....

 

The Paloma and the Morco are very similar in operation, with a fully variable flame size adjuster for coarse temperature control, and a flow regulator for fine control. The Rinnai differs in that although it still has flame size control, it only has two setting, high and low, so if you need something in between (which our shower does),it's hard luck.