Hot water and CH. Boiler decision.

[stegra]

I'm getting myself into a bit of a hole regarding the choice of boiler type. My set-up is a little unusual in that I won't have an engine (electric drive). I will have a calorifier because there'll be a back boiler on the wood burner and hopefully, plenty of surplus solar to put through a 48v dump load immersion heater.

Ideally, I'd like an instantaneous hot supply powered by gas. My idea posted a couple of months ago of directing the pre-heated water from the calorifier to the boiler with some form of bypass valve if it was already up to temperature was quickly struck down. I'm open to the idea of a second coil in the calorifier if it's a must; I guess it just means waiting a while for a shower.

I'd be grateful for any suggestions. I'm very much a "switch it on and it works" type rather than fiddling about with isolating valves and checking temperatures. Also, room-sealed is just massively preferred.

Ta.

[rusty69]

We have calorifier and paloma with change over valve, works fine. The valve is in the kitchen and takes seconds to flip. 

 

Did experiment with solar hot water (flat panel collector) with moderate success, til i busted it. 

[mrsmelly]

5 minutes ago, stegra said:

I'm getting myself into a bit of a hole regarding the choice of boiler type. My set-up is a little unusual in that I won't have an engine (electric drive). I will have a calorifier because there'll be a back boiler on the wood burner and hopefully, plenty of surplus solar to put through a 48v dump load immersion heater.

Ideally, I'd like an instantaneous hot supply powered by gas. My idea posted a couple of months ago of directing the pre-heated water from the calorifier to the boiler with some form of bypass valve if it was already up to temperature was quickly struck down. I'm open to the idea of a second coil in the calorifier if it's a must; I guess it just means waiting a while for a shower.

I'd be grateful for any suggestions. I'm very much a "switch it on and it works" type rather than fiddling about with isolating valves and checking temperatures. Also, room-sealed is just massively preferred.

Ta.

Budget? I have had cheap and expensive boilers. The best is the Hurricane that was awesome but expensive to purchase and when it went kaput it was too expensive to repair for me. I have webasto again at the moment my second boat with webasto. I bought this as a cheap kit from ebay last summer and it has worked faultlessly throughout all last winter and even last week a couple of times when it cooled off. The price difference is massive.

[stegra]

Ah! Webasto. Would they be diesel poweed? I won't have a large diesel tank as no engine to feed, just a generator. I anticipate that the solar will provide plenty of power apart from in the depths of winter or when cruising as the array and battery bank will be oversized for a boat. Neither do I want to be dependent on shore power. I guess when I said ideally gas, I meant, gas.

[rusty69]

4 minutes ago, stegra said:

I anticipate that the solar will provide plenty of power apart from in the depths of winter or when cruising as the array and battery bank will be oversized for a boat

How big an array do you anticipate to heat your water requirements? 

 

 

Edited July 3, 2017 by rusty69

[smileypete]

35 minutes ago, stegra said:

Ideally, I'd like an instantaneous hot supply powered by gas. My idea posted a couple of months ago of directing the pre-heated water from the calorifier to the boiler with some form of bypass valve if it was already up to temperature was quickly struck down. I'm open to the idea of a second coil in the calorifier if it's a must; I guess it just means waiting a while for a shower.

You could feed tepid water (say 25°C) to a Morco D61, using a thermostatic valve.

This would give a much better shower experience in winter, in high summer the water from the tank may be a bit tepid anyway.

Edited July 3, 2017 by smileypete

[stegra]

Just now, rusty69 said:

How big do you anticipate to heat your water requirements? 

Max two quick showers and a bowl of water for the washing up each day.

1 minute ago, smileypete said:

You could feed tepid water (say 25°C) to a Morco D61, using a thermostatic valve.

This would give a much better shower experience in winter, in high summer the water from the tank may be a bit tepid anyway.

I suggested something like that in an earlier thread but was told it was not a good idea. There'll be around 3kw of solar doing not very much unless cruising so I reckon the immersion will probably be enough in good light.

[smileypete]

30 minutes ago, stegra said:

I suggested something like that in an earlier thread but was told it was not a good idea. There'll be around 3kw of solar doing not very much unless cruising so I reckon the immersion will probably be enough in good light.

Biggest problem might be finding a valve that goes down to 25°C, looks like there may be a few out there, or a 30°C one MAY go a bit lower in practice.

[MtB]

I'd suggest fitting a Morco D61 to start with. Nothing wrong with open flue if understood and installed correctly. 

There are room sealed versions but I'd predict you'd regret fitting one. There is an irritating delay in them lighting due to the fan needing to prove when you turn on a hot tap, compared to the almost instantly lighting D61. The delay is particularly annoying as you are pouring precious stored water down the drain all the time while a room sealed boiler stirs itself into life.

And I agree with smileypete, devise a way to feed it with 25C water in winter. This will work excellently.

[stegra]

 

I'd really like to have something room-sealed in a cupboard behind the back door and have the electrical controls there as well. Obviously there'd be quite a bit of heat there so would need good venting. The picture shows the space to the left of the door. There's more room than it appears in the photo. It's 12' beam.

ETA. Sorry. I don't know how I ended up with all these images on here. I can't get rid of them!

 

 

Edited July 3, 2017 by stegra
Incompetence

[smileypete]

ISTR the Morco G11 has a through-wall flue option, the installation PDF should give all the details.

Bear in mind the gas pipe needs to be adequately sized, especially if the cylinders are at the other end of the boat!

[GUMPY]

Fit a decent generator ( https://www.northern-lights.com/marine-generators__trashed/m773lw3-97-kw/ ) and run a 3kw immersion to the calorifier, add a decent charger and it sorts out your battery charging when there is no sun as well