jetzi

The previous design in my boat (which never worked well) had a out and back run, with only a calorifier (no valves), a towel rail (with valves) and one rad (with valves). Directly after the rad the flow and return were connected in a loop. The towel rail never got hot when I tried the eber, the rad got warm but not hot enough. Hence I relied on my solid fuel stove and didn't use the Eber. The rad eventually sprung a leak and so I ripped it and the towel rail out. I assumed there was a problem with the Eber so I had it professionally serviced. I now want to reinstall it - I am thinking that I'll not include the direct connection of the out and back pipes. I'll put valves on all the rads but I will not ever turn the towel rail off. I'll then use the lockshield outlet valve to try to balance the rads. This should work, right?

Since the balance I let the battery run down over 4 days without charging it to try to measure capacity. The BMV showed 470Ah consumed (out of a 640Ah battery) before one of the cells dipped below 3.0V. I probably could have gone lower than that but I'm going to consider that the battery capacity.

Or, don't insulate it and it can contribute to your heating I thought the main reason for not using solid copper on boats was work hardening through vibration. I think as long as the pipe is in the wall and there is space for it to snake, I'll just let it be. There is already quite a lot of plastic pipe in place from the old system. I notice that there is quite a bit of fine rust powder on the inside of this pipe though. So I'm wondering whether I should replace it or if I should just try to flush it out thoroughly.

Thanks, I'll do that. It looks like the valves come with both a "tap" attachment and a "lockshield" attachment so I can use the same one on each side. So that's 6x https://www.toolstation.com/angled-radiator-valve-cp/p15063 and 2x https://www.toolstation.com/inline-radiator-valve-cp/p73348 Totalling 25.84 gbp. Seems fair. For the coolant: 2x skin tanks, external dimensions 1250x480x60 = 36 litres max each (if completely hollow and no skin thickness) = 72 litres 3x double panel rads 1000x600, assuming 10mm thickness uniformly (generous) = 0.6 litres each = 1.8 litres 1x Towel rail is 750*600, assuming 10mm thickness uniformly = 0.45 litres Engine coolant capacity - 7.4 litres 30m of 22mm pipe run for the central heating system = 9.45 litres 4m of 2" pipe for the engine cooling system = 7.8 litres Grand total of about 100 litres of coolant needed... So, 5x of those 20l prestone ready mix coolants which would be 275 quid ? I think I need to find a more affordable coolant...

I have been using Prestone antifreeze/coolant (20 litre ready mixed for 55 gbp: https://www.ebay.co.uk/itm/Prestone-20-litre-Ready-to-Use-Coolant-Guaranteed-for-All-Cars/393232181982) I'm sure it's not the cheapest but it has the advantage of being mixable with any other types of antifreeze. And being that I haven't changed the coolant since I bought the boat, I don't know what kind is in there at the moment. I have been using concentrate mixed with tap water but I would like to replace it with a proper mix of antifreeze and distilled water (or ready mixed like the link). Since I have to drain the cooling system I may as well take the opportunity to replace the coolant. Simplest would be if I can use the same mix for my eber/rad/cauli circuit as my engine/skintank/cauli circuit. I don't mind spending more to get the best.

Great, thank you! I presume each radiator just needs one, and can use a plain elbow on the other side? Lastly regarding the glycol, should I be using the same mixture as I do for my engine/skintanks?

Oh dear, what can be done about this? Use copper? This was extremely helpful to read, thank you! My calorifier coil does not have balance valves, and in fact I think this might have been causing the original problem I had with the Eber - with my radiators only getting somewhat warm, I think what I need to do therefore is to fit manual valves to all 4 radiators AND the calorifier circuit which I can use for balancing, and once balanced, ensure that I never switch off the towel rail. The other radiators I can, if I choose to, use the balance valve to turn off in the Summer months to heat only hot water (and towels). However my expectation is that I'll probably have enough hot water just from solar and from cruising in summer. Does anyone know the name of the valves I'm looking for? Are they just called "Manual radiator valves"? They have inlet sizes of 15mm and come out the sides, except the towel rail whose 15mm inlet valves are at the bottom.

The only controls on my eber is a single pull switch, on/off. If it has a thermostat, I guess it is pre-set to a particular temperature.

Thanks for the help, especially w.r.t. the calorifier not counting as a heat dump. I didn't realise that that was the purpose of the always on radiator. I assumed the purpose of the always on path was to give the pump somewhere to pump the water. It seems rather pointless to have some radiators on while others are off. If it was getting too hot, then wouldn't it be best to turn the Eber off or like @mrsmelly says, open a window? Edit - I'm an idiot, obviously the reason is so that you can still have hot water in Summer while not having radiators on.

It's interesting that you say this is not the normal or best way, because this is the way that I have seen most recommended. Notably, by Will Prowse and by GWL power who sell single cell chargers for this purpose (I almost got a 20A one but glad I stuck with the borrowed 5A lab charger in the end). I guess it is probably recommended because it is the easiest way, with the cells in parallel you can be sure that they are at the same voltage. My understanding was that the emptier cells would take more of the charge coming in. The big downside for me is that the cells had to stay near 100% for 36 hours, which I'm sure took some time off their lifespan. I did my initial balancing last year using a immersion heater element to take off charge from the top cells while my solar MPPT was charging the batteries. I had to do it this way as I didn't have shore power. This was a really tricky operation. Swapping the element between the cells while charging was happening was difficult and probably a bit dangerous. In the end I deemed the cells balanced "enough" but I have a much better result now I feel, because I was able to take the cells right up to 100% instead of trying to balance around the 3.45-3.5V mark. As the cells have been discharging their voltages have also remained closer together.

Yes I did but I can check this again, thanks. I may have got it wrong. Even so, the specs suggest that the relays draw too much current, so I need to change the equipment.

Would the calorifier coil (which has no valves) count as the circuit that is always on? Alternatively, I could just not put a stop valve on the bathroom towel rail, say? Thanks for the link, reading now.

No offence taken! It's definitely is beyond my understanding, though to be fair it all was at the start (and evidently still is, given my oversight with the matching of the Tycoes to the GWL CPM). So I could consider trying to understand how MOSFETs work. However I think the actual answer is that I need to replace either the Tyco relays with a relay compatible with the GWL CPM, or I need to replace the GWL CPM with something that works with the Tycos. Probably the latter, since I may have damaged the CPM by having the relays attempt to draw too much current. My setup is complicated enough without inserting yet another group of relays (I guess I would need 6, one for each coil of each of the three relays).

Thanks, I think I understand what the downside of paralleling them in this way is. In the end I left them overnight, then charged them again to 3.65V (they had subsided to ~3.5V overnight, left them for a few more hours and then charged again to 3.65V. So they were at 100% for about 36 hours which is longer than I'd like but I'm feeling pretty confident that they were well top balanced. Although the lab PSU said it was rated at 5A, the charge current was actually in the 3.5A to 4A range. I'm now taking them down to 3V each before I charge them up again, to check capacity and to try to reset any memory effect. I think this will be about 20%. They have been wonderfully in sync the whole way down so far. After reinstalling, I'm a bit concerned about my GWL cell performance monitor. When I turned it on, my Tyco relays failed to trigger, so I don't know that I can trust it to shut off my battery. I tested each of the relays by applying current manually and they are all working, so the problem seems to be in the CPL board. I'm going to contact GWL and see if they know what the problem is. As a precaution I think I'm going to buy one of @Dr Bob's motorised BEP switches and drive it from my BMV712 on low voltage.

I'm not sure if you're serious but I'm actually seriously consididering it. I feel like a stop cock on each rad is still warranted so I can turn off and on rooms at will. Another question, while I'm at it I'm going to replace the coolant in my engine (since I will have to drain it to replace the cauliflower anyway). Should I use the same stuff in my central heating system? It's going to be a reasonably large volume so I imagine it will get quite expensive...

I'm installing 3 new rads and a towel rail driven from my 4.1kW Eberspacher. It also has a coil in my calorifier. Is it correct to connect TRV valves if they are being driven from an Eberspacher? I'm looking at these on eBay (8,54 GBP per set of TRV valve and lock shield... I need 4). Or is it best to connect a plain stop cock? Also, the previous circuit had a big loop of pipe with radiators in parallel off that pipe. The black arrow in the diagram points to what I'm speaking about - is it necessary to connect the hot feed directly back to the Eber like this? I thought maybe it was for in case all the radiators TRVs were off so that the Eber pump has a complete circuit. But the calorifier is "always on" so it doesn't seem necessary, and I should have thought it would work more effectively if there wasn't a short cut for the hot water.

When you say "top balance under charge conditions" do you mean take the cells up to full from say, half, rather than from ~80% or ~90% as I did today? I did balance under charge conditions but not for very long (2-3 hours max). I believe that the way that it would work is that the charger would have put the energy into the three flatter cells rather than the 100% cell. I'll leave them overnight and then disconnect and see what the cells in isolation are. But I don't really want to leave the cells near-full for multiple days, so I might just accept a slightly less than perfect balance.

Balancing. I just did a proper top balance of my LiFePO4 cells. Beautiful day here so I charged them up via solar until one cell was full (actually I blinked and it was a little overfull at 3.7V - oops), the other three were at 3.4V at this point. I connected them all in parallel and they averaged out to just below 3.5V. I then used a lab charger to take them all to 3.651V, which was surprisingly fast (~2hours at 5A) since they started almost full. I'm thinking that I should leave them connected in parallel overnight to ensure that they have time to properly sync in charge. Or is this not reallly necessary and if they are 3.65V in parallel then they are equalised? On the other hand, I don't want to leave them full for too long. Particularly since one of the cells started a little overfull. Thoughts?

I don't really care for marinas so I don't expect to spend much time on short pontoons, really just looking for a temporary improvement so I can get some shuteye tonight! Won't buy a mudweight but I could go hunt for a rock or use my anchor (though it sounds like that's inadvisable for some reason. I also just realised that part of the reason I "slept so badly" is because my clocks (automatically) went forward last night, so I got an hour less than I thought ? I think a daylight savings nap might be in order today...

Yeah, carpet tiles hung at strategic points seems a good idea. Are cats smart enough to use them? I feel like the mankiness is going to be rapid onset and particularly foul... This happened to my cat! I said he's fallen in "two or three" times because I'm not sure one of the times actually counted. He fell in and was back on the bank almost before he started, almost completely dry. It defies physics. Twice though he's gotten properly wet, didn't have his head go under but it was very cold and a bit dirty so I gave him a warm bath both times afterwards. He seemed to hate even more than the initial fall in the canal (I really thought he'd like the warmth... but no... even so he sleeps in my bed and I'm not keen on having canal in bed with me). Two tshirts and a curtain later (never mind my skin) he was clean and drying himself in front of the stove. And extra soft for the next couple of weeks which was a bonus. The boat has cylindrical rope fenders but he swam right past them to get to the bow. I'm not sure if he would have used them if I wasn't there to rescue him. I actually think the next time it happens I should give him a chance to climb out to see if it's possible. I'm glad you found him. I must admit it was maybe not a smart choice to get a cat on a boat. But he's a really great companion and it really helped to have SOME company during lockdown. He loves going outside and I feel like it would be cruel to confine him to just the boat cabin, it's not a lot of space. Babbage looks very sweet. I notice the bank behind you has the normal "crash barrier" style ties, probably the most common canal edge, is she able to climb out onto those? I think some kind of clawable cloth seems the answer.

The washing up liquid has reduced the creak to about 20% of what it was, so that's probably good enough for me! Thanks everyone. I do notice that my ropes (not just from this but from years of use) have worn through a couple of layers of paint. I think when I repaint and replace the ropes, I'll thread a bit of plastic pipe on each of them with a knot to keep it in place, apart from creaks, hopefully that will also protect the paintwork a bit? Definitely part of it, but the main problem is that the pontoon is less than half the length of my boat. So although she's tied at the stern and around halfway, the lever arm means that the bow swings back and forth about a foot like a pendulum. This seems like a good idea, but I don't think any of my ropes are quite long enough (yeah, I need new ropes). The basin is nearly empty, I guess I could sidle up to another long boat but that would probably be kind of like using an adjacent urinal in an empty gents'! I'm not entirely sure what a mudweight is but I don't think I have one of these. I do have an anchor which I've never used. Would a small boulder tied to a rope count? Good idea to tie to the opposite side to reduce the sharpness of the angle, I will do that. Unfortunately I have no attachments at gunwale level, all my fenders attach to the hand rail at roof height. What is the way to sink it, attaching on both port and starboard? If the water rises enough to duck the boat under, surely attaching to just one side would also sink the boat by rolling it over? Or am I misunderstanding you? I also kind of like it, or rather, I want to like it, but I had a poor night's sleep last night because the creaks would rouse me. Other than that the sounds don't bother me, I am a light sleeper I guess. @Alan de Enfield The diagram below shows what I'm currently doing (in red) and what I think you're suggesting (in dashed blue). Is this correct?

Will try washing up liquid, thanks! When you say you need more than one attachment point to the pontoon, do you mean more than my stern rope and my midline?

As it's a boating forum I should explain that I'm talking about felis catus or common domestic feline, not a catamaran... He's a bit dim and likes to scuttle up and down the gunwale, and it has happened two or three times that he lost his footing and landed in the cut. He's a surprisingly good swimmer and each time swam half a boat length around to the bow. Fortunately for him I've been around to fish him out, because I'm not sure the soggy moggy would be able to climb out of the steep banks of most canals. And he surprisingly didn't have the wherewithal to meow, so it was just the splashing i had to alert me. Does anyone have any suggestions for keeping my cat from drowning? Some kind of ladder for him to get out by himself would be best I suppose, but it would probably also get quite dirty quite quickly. A more high tech solution would be a water-sensitive buzzer I could attach to his collar, but I don't know if such a thing exists. Any ideas welcomed!

I've never moored perpendicularly to the bank before so I don't know if I'm doing it wrong. No one next to me. The pontoon is only about 30' long so I'm moored to a cleat at the stern, but I obviously can't use the bow rope (since my boat is 65'). I have two midlines, which are affixed to each hand rail on my boat, rather than a centre ring. I tied the port midline to the cleat at the end of the pontoon as tightly as reasonable, but there's a bit of a breeze and the boat swayed around causing the rope to creak against the handrail. So, I tied the starboard midline to the pontoon on the OTHER side (across the gap wehere another boat could wedge me in nicely). This helped but the creaking is still happening and on both sides now. It's keeping me awake. What's the correct way to moor to a short pontoon? And is there anything I can do to stop creaks? I'm about to douse the ropes in WD40...

Wow, does this work? Essentially turning the Calorifier into a thermal store like @peterboat suggested! Does this mean the calorifier circuit needs to be in series with the radiators, otherwise wouldn't it just circulate through the alde? I am not sure if I can turn the circulation on the Eber on without the Eber being on, but it's worth tinkering with to find out. Thanks, great suggestion, I think I will experiment with this rather than trying to buy a heat exchanger and mess with the engine cooling.