Instant gas hot water

[PabloC]

Hi all, I'm looking to install an instant gas hot water unit. 

I've seen Rinnai are fairly popular, but as far as I can see these require 230v and I know there are units that are ignited using replaceable batteries.

Does anyone have any suggestions on alternatives to Rinnai? I've seen plenty, but unsure of the build quality. 

 

 

As an aside, we do have an immersion and calorifier fitted for hot water, but my understanding is this wouldn't be an effective system for a couple of brief uses of hot water a day.

We have shore power available if necessary. 

 

Thanks in advance

 

 

[Crewcut]

If you have shore power then I would just use kettle or immersion depending on quantity of HW required. I have heard people say that once the water tank is up to temperature it doesn't cost a great deal to just leave it on to keep the water hot...

[Tracy D'arth]

39 minutes ago, PabloC said:

Hi all, I'm looking to install an instant gas hot water unit. 

I've seen Rinnai are fairly popular, but as far as I can see these require 230v and I know there are units that are ignited using replaceable batteries.

Does anyone have any suggestions on alternatives to Rinnai? I've seen plenty, but unsure of the build quality. 

 

 

As an aside, we do have an immersion and calorifier fitted for hot water, but my understanding is this wouldn't be an effective system for a couple of brief uses of hot water a day.

We have shore power available if necessary. 

 

Thanks in advance

 

 

With the ever rising price of bottled gas, I would stay on the immersion unless your electricity supplier is ripping you off. You do know that the supplier can only charge the price they pay for the electricity?

[Arthur Marshall]

I have a Rinnai, uses a battery for the ignition. Modek REU-58E.

ETA Not sure if this is ok for a new installation as it's not room-sealed.

Edited June 1, 2022 by Arthur Marshall

[Tracy D'arth]

8 minutes ago, Arthur Marshall said:

I have a Rinnai, uses a battery for the ignition. Modek REU-58E.

ETA Not sure if this is ok for a new installation as it's not room-sealed.

No, its not approved unless its Balanced or forced flued on a new installation.

[roland elsdon]

Gave up on gas hot water. We have a very small calorifier that is 12v or mains. We dont have a mains system so it runs off the domestic batteries.

Before i get the usual rash of comments about how inefficient it is I know.

However with an air cooled engine a hysteric boat and Minimal space we have no choice.

We boat not sit and 3 hrs boating gives us 10 litres of hot water.

A lot easier than faffing with gas systems diesel systems vents etc.

[Arthur Marshall]

2 hours ago, roland elsdon said:

Gave up on gas hot water. We have a very small calorifier that is 12v or mains. We dont have a mains system so it runs off the domestic batteries.

Before i get the usual rash of comments about how inefficient it is I know.

However with an air cooled engine a hysteric boat and Minimal space we have no choice.

We boat not sit and 3 hrs boating gives us 10 litres of hot water.

A lot easier than faffing with gas systems diesel systems vents etc.

I'm just glad I started this lark before all these daft rules came in. Gas fridge, gas hot water, one domestic and one starter battery has sorted me for thirty years.

[MtB]

3 hours ago, Tracy D'arth said:

No, its not approved unless its Balanced or forced flued on a new installation.

 

 

Not approved by whom exactly, for compliance with what, exactly?

 

BSS you mean? I've not noticed anything in the BSS about this.

 

 

 

 

Edited June 1, 2022 by MtB
Clarify my question

[Tony Brooks]

1 minute ago, MtB said:

 

 

Not approved by whom exactly, for what?

 

BSS you mean? I've not noticed anything in the BSS about this.

 

 

 

Possibly the ISOs for the RCD/RCR.

[MtB]

1 minute ago, Tony Brooks said:

 

Possibly the ISOs for the RCD/RCR.

 

 

The OP sounds as though this is not a new boat, in which case who gives a frying flukc about the RCD/RCR? 

[Tony Brooks]

Just now, MtB said:

 

 

The OP sounds as though this is not a new boat, in which case who gives a frying flukc about the RCD/RCR? 

 

Alan? Although there is a small chance that on a post 1998 boat ignoring it may come back and bite the owner.

[MtB]

2 minutes ago, Tony Brooks said:

 

Alan? Although there is a small chance that on a post 1998 boat ignoring it may come back and bite the owner.

 

 

Yes Alan cares, but nobody else! 

 

Point being, yes if the boat is RCD/RCR adding an open flue appliance offends BS PD 54823:2016 but nobody would know or care because nobody enforces it, because it is only for those who are scared of their own shadow or those who enjoy box-ticking. 

 

 

[Alan de Enfield]

28 minutes ago, MtB said:

 

 

Not approved by whom exactly, for compliance with what, exactly?

 

BSS you mean? I've not noticed anything in the BSS about this.

 

 

 

 

 

The BSS are reviewing the use of open-flue appliances - they have said, for many years. that they only allow open flue water heaters on concession until sealed flue equivalents are readily available.

 

It appears that time may now have come - there are now sealed flue appliances readily available.

 

 

For non-private boats the use of sealed flue appliances has been mandatory for many years - it is the inclusion of this for Private boats which is under review :

From the BSS:

 

Appliances which are not room-sealed but which were installed before 3 January 2000 can continue to be used, as long as they are serviceable and in good condition.

Replacement and additional new appliances to the boat must be of the roomsealed type, except for cooking appliances and, in the absence of a direct replacement, instantaneous water heaters.

To help ensure continued safe operation of an appliance any modifications or additions to an existing appliance must be performed in accordance with the manufacturer's guidelines. Defective or inappropriate components could lead to a gas leak or inefficient combustion and the production of noxious gases. [8.2]

[MtB]

Just now, Alan de Enfield said:

 

The BSS are reviewing the use of open-flue appliances - they have said, for many years. that they only allow open flue water heaters on concession until sealed flue equivalents are readily available.

 

It appears that time may now have come - there are now sealed flue appliances readily available.

 

 

For non-private boats the use of sealed flue appliances has been mandatory for many years - it is the inclusion of this for Private boats which is under review :

From the BSS:

 

Appliances which are not room-sealed but which were installed before 3 January 2000 can continue to be used, as long as they are serviceable and in good condition.

Replacement and additional new appliances to the boat must be of the roomsealed type, except for cooking appliances and, in the absence of a direct replacement, instantaneous water heaters.

To help ensure continued safe operation of an appliance any modifications or additions to an existing appliance must be performed in accordance with the manufacturer's guidelines. Defective or inappropriate components could lead to a gas leak or inefficient combustion and the production of noxious gases. [8.2]

 

 

You do make me laugh Alan.

 

1) BSS been 'reviewing' open flue appliances since the dawn of time.

 

 

Go on, do quote the BSS rule banning them.

 

[Guest]

Hi all 

 

Just for the record, if you can have a read of ISO 10239:2017 you will see that open-flued water heaters are fine to be installed. There are some conditions (not in a bathroom, must have auto shut off in the draft diverter eg OSD) but it’s no issue on any boat, new or old. Look it up, but you will need to buy the standard unfortunately. It’s at point 7.4.2. 

As you probably know standards are guidance only. For those who know UK law, and in particular GSIUR, have a look at the rules on room sealed / open flued water heaters, and you will see that it is also ok to install open flued appliances  (with conditions) - these are briefly OSD, not in a bathroom and if in a bedroom (so a boat) less than 14kw. This you can read for free on gov web. Think it is reg 30(3). Those in the gas world will already know this though I’m sure. 
 

The ‘replacement only’ option in PD54823 document is erroneous really; it doesn’t state that anywhere else in the world. It’s misplaced guidance and uk law (GSIUR) trumps it every time. 
 

The BSS position is clear, open-flued appliances are fine. You can read that in the 2021 interim guidelines. No change is coming there. You can look at check item 8.10.2 and 8.10.4 and there is no qualifier on age. 

 

https://www.boatsafetyscheme.org/media/299267/bss-examination-checking-procedures-core-2-9-interim-final.pdf

 

If in doubt, why not ask the BSS themselves and come back with the answer? 

Happy to discuss, but please quote fact and source if you make assertions, as it’s easier to debate and get to the truth. 

[MtB]

12 minutes ago, watchfuleye said:

The ‘replacement only’ option in PD54823 document is erroneous really; it doesn’t state that anywhere else in the world. It’s misplaced guidance and uk law (GSIUR) trumps it every time. 

 

Point of Order M'Lud.

 

Good post, but the GSIUR only apply to boats which are a dwelling. (Or mebbe it says 'residence'.)

 

Leisure boats are outside of the scope of the GSUIR, unless you can demonstrate otherwise. And I doubt you can. 

 

 

[roland elsdon]

My first boat had a paloma, not even flued out. Second boat i fitted paloma but flued through mushroom vent.

Somehow I survived paloma water heaters from 1980 to 1996., as well as gas fridges, and catalytic heaters.

We had no gas certs no certificates of compliance no smoke alarms no co monitors, no mains rings and no corgi gas fitters, no inverters .Hell first living  boat had one battery and a dynamo. solar panels were for nasa.

Phones took 2 p and we walked across the park in the rain to make calls.

How did we come through it?

 

 

 

 

 

[Balloon]

We have a Mountainair Fastar which I’ve seen people slag off loads because they’re cheap - but it’s flawless and works with battery ignition. (It’ll break now I’ve praised it). 
 

[Tracy D'arth]

26 minutes ago, Balloon said:

We have a Mountainair Fastar which I’ve seen people slag off loads because they’re cheap - but it’s flawless and works with battery ignition. (It’ll break now I’ve praised it). 
 

MountainNet Fastar heater, there was on on ebay.

[Slow and Steady]

I've wondered if I could plumb my webasto for direct hot water as I don't use it for heating. There must be a way and it's pretty darn quick. Possibly rather uncontrollable though and a bit slow to start up and stop.  OK, yes, that was a stupid idea.

Edited June 1, 2022 by Slow and Steady

[Balloon]

7 hours ago, Tracy D'arth said:

MountainNet Fastar heater, there was on on ebay.

Thanks. I knew it sounded wrong somehow but couldn’t be bothered to get out of bed to look at it 🤣

[Balloon]

11 hours ago, Arthur Marshall said:

I'm just glad I started this lark before all these daft rules came in. Gas fridge, gas hot water, one domestic and one starter battery has sorted me for thirty years.

Are you not allowed a gas fridge any more? We always had one when I was growing up on our boats and I was considering getting one for my boat the other day. 

[Alan de Enfield]

3 hours ago, Balloon said:

Are you not allowed a gas fridge any more? We always had one when I was growing up on our boats and I was considering getting one for my boat the other day. 

 

I think Arthur is 'over egging the pudding' a little to make a point.

 

Yes you can have a gas fridge - unless you have a petrol engine. (Petrol fumes and a naked flame low down in the boat do not play well together - well they do, but only one-time)

[Tracy D'arth]

3 hours ago, Balloon said:

Are you not allowed a gas fridge any more? We always had one when I was growing up on our boats and I was considering getting one for my boat the other day. 

Have you seen the price of gas?

[Ex Brummie]

10 hours ago, Slow and Steady said:

I've wondered if I could plumb my webasto for direct hot water as I don't use it for heating. There must be a way and it's pretty darn quick. Possibly rather uncontrollable though and a bit slow to start up and stop.  OK, yes, that was a stupid idea.

The nature of an oil burner flame, with prepurge and a concentrated flame, does not lend itself to instant DHW in the same way that a gas flame will instantly light over a wide area and heat up two cupfuls of water. If you look at oil fired combis, they all have a heatstore (or use the boiler body) to feed  the DHW heat exchanger.

Edited June 2, 2022 by Ex Brummie