Plumbing! Seeking general advice...

[Alan de Enfield]

Just now, system 4-50 said:

I also prefer to have my pump above the level of the top of the tank.

Our pump actually sits on top of the tank.

[GUMPY]

5 minutes ago, blackrose said:

 

I think it does if it's only plumbed in 15mm pipe on the low pressure side as it can struggle to get enough water through.

Nope

Both Parglena and Loddon are in 15mm and no problems with flow on either system with  about 40 ft of pipe work feeding the pump

Edited June 13, 2020 by Loddon

[ditchcrawler]

6 hours ago, Boaty Jo said:

Check valves hot and cold on all appliances. They will need service / replacement.

What do you class as an appliance?

 

1 hour ago, Loddon said:

When I say at the back one is not right at the back.

It is between the kitchen and bathroom so the outlet from the pump went to a T feeding in two directions.

 

It really doesn't matter where the pump is in the layout

Mine is under the galley cupboard

 

1 hour ago, Loddon said:

Nope

Both Parglena and Loddon are in 15mm and no problems with flow on either system with  about 40 ft of pipe work feeding the pump

Same here

[Slim]

13 hours ago, Loddon said:

Last two boats I have had the pump and accumulator have been near the back of the boat with the tank at the front. Works fine.

 

Also go for the bigger accumulator saves the pump coming on when the bog is flushed mine is 5L

My pump is mid boat with 5l accumulator downstream of it, no problems or issues.

[Jen-in-Wellies]

2 hours ago, Loddon said:

Nope

Both Parglena and Loddon are in 15mm and no problems with flow on either system with  about 40 ft of pipe work feeding the pump

Same here. A 11 litre/min rated Jabsco pump will push 4 to 5 l/min through the 15mm pipe on my boat to a tap. Enough to run a bath, or sink full at a perfectly reasonable flow rate, but not both simultaneously. Happy with that.

Jen

Edited June 13, 2020 by Jen-in-Wellies

[Ex Brummie]

It is worth bypassing the pump pressure switch with a more robust external unit, where you can adjust the switching differential. Repetitive cycling can soon frazzle the lightweight built in switches.

[Murflynn]

14 hours ago, WillCful said:

The hot water comes from the water heater, it’ll be a instant gas water heater I am considering the Cointra CPA11. I haven’t shown the gas lines. 

no calorifier then?  (free hot water when cruising).

[WillCful]

That’s great thank you guys. 
 

The pump is where it is because I’ve built an accessible location behind the shower, initially for the gulper but there’s space for both and it means I’ve got more space at the front of the boat by the tank.

 

Thats an interesting article, I guess there will be dedicated disposal points for composting toilets as they become more widely adopted. Bit like electric car charging points ?

 

Funny, the branded accumulators (well, Jabsco ones) are about twice the price of a normal small metal expansion tank.

46 minutes ago, Murflynn said:

no calorifier then?  (free hot water when cruising).

Nah, not gonna be cruising that often. I’m gonna build in a space under the bed so that I can add one at a later date if I change my mind...

[Jen-in-Wellies]

20 minutes ago, WillCful said:

Funny, the branded accumulators (well, Jabsco ones) are about twice the price of a normal small metal expansion tank.

There is a difference between accumulator/expansion tanks designed for potable water and ones that are not and used on central heating systems. It is reflected in the price.

[Onewheeler]

4 hours ago, BEngo said:

Drain valves are there to let the water out of the pipes so it does not freeze and burst them. You need one at every low point in the system. Look like this:

https://www.jtmplumbing.co.uk/pipe-fittings-c433/compression-valves-15mm-28mm-c41/jtm-drain-off-type-b-p903/s905?utm_source=google&utm_medium=cpc&utm_term=jtm-drain-off-type-b-15mm-size-15mm-size-15mm-bfdoctb-15na&utm_campaign=product%2Blisting%2Bads&cid=GBP&gclid=EAIaIQobChMIl4Teu6b-6QIVg7HtCh3BsQ-SEAQYBCABEgKp_PD_BwE

You need to be able to get a  tub under them.

I have an intense dislike for that sort of drain valve. The sealing washer has a habit of gluing itself in place when they get old, which means having to pull the innards out to make it drain. My preference is a ball valve (washing machine valve) as they're less prone to sticking.

[WillCful]

1 hour ago, Jen-in-Wellies said:

Same here. A 11 litre/min rated Jabsco pump will push 4 to 5 l/min through the 15mm pipe on my boat to a tap. Enough to run a bath, or sink full at a perfectly reasonable flow rate, but not both simultaneously. Happy with that.

Jen

Ah that’s interesting, I didn’t consider the restriction the pipe would put on flow rate. I guess the water heater will be receiving the same flow rate, so I could get away with a lower rated (and slightly cheaper) water heater (Cointra CPA6 which does 6lpm) Or, plumb the whole boat in 22mm to take advantage of the pumps capabilities... Would higher flow rate make for a ‘better’ shower? I’m not fussed about being able to run more than one appliance at a time. 

[Jen-in-Wellies]

24 minutes ago, WillCful said:

Ah that’s interesting, I didn’t consider the restriction the pipe would put on flow rate. I guess the water heater will be receiving the same flow rate, so I could get away with a lower rated (and slightly cheaper) water heater (Cointra CPA6 which does 6lpm) Or, plumb the whole boat in 22mm to take advantage of the pumps capabilities... Would higher flow rate make for a ‘better’ shower? I’m not fussed about being able to run more than one appliance at a time. 

"Better" as in wetter! The path to something flow rate critical, like a shower would be important, so tank to pump to heater to shower would be better done in 22mm I think, given the choice. The rest could be in 15mm to kitchen sink and wash basin. For your boat, all in 15mm may well be fine. 22mm to the critical stuff reduces the small probability that it won't. I don't know the water heater, but it is possible it might shut itself down due to overheating if the flow rate to it is not sufficient.

[ditchcrawler]

1 hour ago, Onewheeler said:

I have an intense dislike for that sort of drain valve. The sealing washer has a habit of gluing itself in place when they get old, which means having to pull the innards out to make it drain. My preference is a ball valve (washing machine valve) as they're less prone to sticking.

Avery time, poking a terminal screwdriver and hoping to stem the flow is fun

[blackrose]

5 hours ago, Loddon said:

Nope

Both Parglena and Loddon are in 15mm and no problems with flow on either system with  about 40 ft of pipe work feeding the pump

 

Well your experience is different from mine so it might depend on the pump or other aspects of the system. Mine struggled to get enough water through a 15mm pipe at about 25ft from the tank. As soon as I moved it much closer to the tank it solved the problem so it's definitely a factor to be considered.

Edited June 13, 2020 by blackrose

[bizzard]

Gas Instantaneous water heaters don't always work well with an accumulator in it's circuit. When taking a shower for example they like a steady pressure, tick, tick, tick, rather than a bit of a variable pressure that accumulators tend to do,  that might keep putting the flame out.

[cuthound]

3 hours ago, Jen-in-Wellies said:

There is a difference between accumulator/expansion tanks designed for potable water and ones that are not and used on central heating systems. It is reflected in the price.

 

Indeed, and the ones designed for central heating systems soon corrode because potable water doesn't have corrosion inhibitors in it.

[WillCful]

Varem Expansion Vessel Potable 2 Litre With Check Valve https://www.amazon.co.uk/dp/B00GRR54DI/ref=cm_sw_r_cp_api_i_-qp5Eb5HSG8W7
 

So something like this claims potable but if it’s carbon steel as claimed in the description I think it would probably corrode... I guess a copper one would be needed really. 
 

Ah, this one looks good... good price too.

 

https://www.completepumpsupplies.co.uk/reflex-potable-2-litre-expansion-vessel-shock-arrestor?utm_source=google_shopping&gclid=CjwKCAjw8pH3BRAXEiwA1pvMsR3QVMKm5bhSHFGh6-WhEWzF2HHRaNa0gq8VAEer0GnT45fMI9F6tBoCibMQAvD_BwE

Edited June 13, 2020 by WillCful

[GUMPY]

Been thinking about this, cant check as boat is 250 miles away, my expansion vessel is 25litres not 5.

When showering I get a wet down from one charge, and a rinse off from the next. To save water I turn the shower off between actions (navy showers https://en.m.wikipedia.org/wiki/Navy_shower )

It takes about a minute and a half to recharge once the pump kicks in.

Quite different from other boats but works for us.

[Ex Brummie]

On ‎13‎/‎06‎/‎2020 at 16:46, WillCful said:

Varem Expansion Vessel Potable 2 Litre With Check Valve https://www.amazon.co.uk/dp/B00GRR54DI/ref=cm_sw_r_cp_api_i_-qp5Eb5HSG8W7
 

So something like this claims potable but if it’s carbon steel as claimed in the description I think it would probably corrode... I guess a copper one would be needed really. 
 

Ah, this one looks good... good price too.

 

https://www.completepumpsupplies.co.uk/reflex-potable-2-litre-expansion-vessel-shock-arrestor?utm_source=google_shopping&gclid=CjwKCAjw8pH3BRAXEiwA1pvMsR3QVMKm5bhSHFGh6-WhEWzF2HHRaNa0gq8VAEer0GnT45fMI9F6tBoCibMQAvD_BwE

The water does not come into contact with the metal on a potable vessel. There is a bladder inside that contains the water. The metal vessel is pressurised to allow the bladder to expand . I don't know what the check valve is, if one is supplied with it, DO NOT fit it. The water must be able to pass back and forth unrestricted.

Edited June 14, 2020 by Ex Brummie

[Ex Brummie]

On ‎13‎/‎06‎/‎2020 at 14:53, bizzard said:

Gas Instantaneous water heaters don't always work well with an accumulator in it's circuit. When taking a shower for example they like a steady pressure, tick, tick, tick, rather than a bit of a variable pressure that accumulators tend to do,  that might keep putting the flame out.

Depending on the pump output and the capacity of the heater, I agree up to a point. However, if the accumulator is set up right, then there will still be sufficient pressure and volume to maintain the heater. In fact, if you want to use a mixer valve, or operate a mixer tap, an accumulator is essential. And if running a 6 litre heater on a pump that supplies 12 lt or more, the limited pipework to an instantaneous heater will make the pump pulse, and impairing the heater operation.

[Bod]

Keep the number of joints to a minimum, where possible those joints should be easily accessable, when the fit-out is complete.

Fit isolation valves, at each appliance, and drain valves where necessary.  Better design at this stage will prevent much trouble later on.

"WHO THE H*** fitted that there?"  well you did.....

Remember it will be you, who has to fix faults.

 

Bod.