Eberspacher - replace the old one or buy new - what would you do?

[pvb]

We have water tanks under both saloon berths.

How about the space behind the backrest? Or indeed via the lockers above? Only needs to be a smallish diameter duct.

 

[mattnj]

I am a big advocate of wet systems, but only when I can load the boiler correctly with radiators and will, along with a number of my colleagues no longer use matrix due to past customer dissatisfaction, the small coolant volume and the matrix performance at the temperatures produced are simply unsatisfactory and cause cycling and premature coking. A matrix claimed at for instance 5kw will not produce anything like that at evaporator boiler coolant temperatures, couple them to your engine coolant and they come into their own.

I'm worried now, as I am about to plumb in my ThermoTop with 2 x 5kw matrix + calorifier.
All works fine on the bench test, although that is with a large bucket in the system and going through a 20m long bit of coolant pipe...

What are the options to improve the situation? I don't think radiators are an option, I can possibly do a couple of v small towel rails in the heads, what about underfloor type heating pipe, easy enough to run 20/30m of that all round the boat, I have all the floor up, lockers empty and am re-cabling....or is the whole system doomed before I start :ambivalence:

Or a few of these in the system, in the lockers?

View attachment 46612

 

[fireball]

Or a few of these in the system, in the lockers?

View attachment 46612

Oo ... heated seats ... or as I call them (in the car) - Warmyourbotties ...
Put a couple under the cockpit seats (with diverter valves) and you can have warm winter sailing!

 

[David2452]

I'm not so sure about underfloor, the plastic pipe doesn't really rip enough heat out, I have used it on large boats but that was with P.J. boilers which are an entirely different kettle of fish. To be really blunt, only radiators seem do it properly and even then only if there are enough, the exception would be the matrix with large headers that I mentioned earlier. If you were able to get a lot of 22mm copper pipe in there somehow it would help, it dumps about 60w per metre at evaporator boiler temperatures.

 

[David2452]

How about the space behind the backrest? Or indeed via the lockers above? Only needs to be a smallish diameter duct.

Small duct is unlikely to perform well, the first vent will need to be a permanently open one and the back pressure from the small (say 60mm) at anything over a couple of metres tends to reduce the volume output as a great deal of it just goes through the always open vent. It will work obviously but the performance will not be close to what it would be with the 90mm stuff.

 

[pvb]

Small duct is unlikely to perform well, the first vent will need to be a permanently open one and the back pressure from the small (say 60mm) at anything over a couple of metres tends to reduce the volume output as a great deal of it just goes through the always open vent. It will work obviously but the performance will not be close to what it would be with the 90mm stuff.

True, but you don't need a huge amount of heat in a forepeak.

 

[Scotty_Tradewind]

what fuel are you using BTW?
.

Hi David,
Red diesel from the main tanks.

I do notice that the back of the matrix's closest to the fans are fairly bocked with detritus so that may also be causing heat to be circulated rather than blown out (?)

S.

 

[Scotty_Tradewind]

True, but you don't need a huge amount of heat in a forepeak.

MrS. does..... makes apre' sail more the merrier too!

S.

 

[David2452]

True, but you don't need a huge amount of heat in a forepeak.

You might not, < 23 in < 5 outside and both I and SWMBO are not staying on the thing.

 

[David2452]

Hi David,
Red diesel from the main tanks.

I do notice that the back of the matrix's closest to the fans are fairly bocked with detritus so that may also be causing heat to be circulated rather than blown out (?)

S.

May be contributing, but I think you have already self demonstrated the drawbacks of such a system.

 

[Otter]

Laurin, go to the D4, you've seen the size of LK and she only just stays warm with a D4 when it's freezing outside. Do you intend to stay at anchor overnight? If not and its just for the marina, then keep your current Eber as background heat and some electric rads in the saloon and forepeak would do nicely.

Don't dismiss second hand, we bought the D4 from a reputable dealer on eBay and it looked new, it had been completely stripped and cleaned and came with a six month warranty. £600 if I remember. If it doesn't work out of the box then PayPal will give you a refund and a professional installer will tell you straight away if it's sound. Steer clear of blokes selling ones stripped out from a vehicle and uncleared and no warranty, you see some absolute rubbish.

 

[nimbusgb]

Why not fit a second small unit forward to heat just the forepeak.

 

[David2452]

Why not fit a second small unit forward to heat just the forepeak.

Where do I start? because the smallest currently available unit is 2kw and would melt you, because the cost would be silly money when compared to a properly specified and installed single unit. Because the distance from the tank would present issues with the dosing pump, because one would have problems correctly and safely routing the exhaust with a heater installed in such an area, those reasons apart it's a brilliant idea.