Diverter valve

[Ray]

When we decided to get a boat we planned to cruise occasionally and to spend a lot of weekends on it at our mooring. When we designed the plumbing we worked to the concept that the engine would provide the hot water and an Alde would heat the radiators, completely forgetting that when we're on the mooring we wouldn't really want to run the engine just for hot water.

 

Once we realised our error we modified the plumbing so that the Alde can heat both calorifier and radiators either singularly or both together - the latter's been quite useful with the summer that we're experiencing this year! We put a T in the outlet from the Alde and then put a manual gate valve in each branch from the T so that we could isolate which ever circuit we wanted to. We also put a remote switch to control the Alde's pump when we just wanted to heat the water. The room stat that comes with the Alde controls the heating to the radiators.

 

The gate valve in the radiator circuit is under the side of the bed at floor level - luckily the bed pulls out to provide access. The gate valve in the calorifier circuit is near the calorifier and requires the bed to be pulled out and a removable panel at the foot of the bed to be lifted out to gain access to the valve.

 

At present the gate valve supplying the radiators is shut and the calorifier gate valve open. We usually flick the remote switch to start the Alde's pump and leave this on until we remember to turn it off when we want hot water. As a result we may be overheating the hot water and wasting gas.

 

Our domestic plumbing at home has just had to be repaired and this set us thinking about fitting a cylinder thermostat to the calorifier on the boat and wiring the above mentioned remote switch through this, such that the pump would only come on when the cylinder stat on the calorifier demanded heat. As we turn the Alde and the electric off when we're not on the boat we wouldn't need to worry about it being left on when we're not there, not would we need to worry when we're crusining because we'd turn the remote switch off anyway, leaving the engine to heat the calorifier.

 

We've seen a cylinder stat in the Screwfix catalogue that looks as though it will do what we want. However, our thoughts have now gone a stage further.

 

We were wondering whether we could fit a standard domestic diverter valve in place of the T and the two gate valves to avoid the need to keep pulling the bed out to get to the manual valves. We might leave the gate valves in place in case we only want to drain part of the system. The diverter valve needs to be able to be mounted such that it doesn't lengthen the pipe runs if at all possible. This means that it will be at floor level where access is not the easiest thing.

 

Standard diverter valves appear to work off 230v, but as we've got an inverter plus a land line when moored, we don't think that this would be a problem although, obviously, a 12v circuit would be a much better idea. The slight disadvantage of the idea is that only one of the two circuits could be open at a time - the present arrangement allows both, but I thnk that we could live with this as we only heat the radiators very occasionally when moored, preferring the stove when longer periods of warmth are required.

 

Has anyone got a setup like the one we're thinking of and/or does what we suggest seem reasonable/workable? Has anyone got any other ideas to save the fumbling around at floor level? In an ideal world I could see benefits in having the two thermostats control the diverter valve as well as the Alde pump. although I suspect that we'd need to use a relay to do this to keep the 12v and 230v circuits separate.

[bottle]

Standard diverter valves appear to work off 230v, but as we've got an inverter plus a land line when moored, we don't think that this would be a problem although, obviously, a 12v circuit would be a much better idea. The slight disadvantage of the idea is that only one of the two circuits could be open at a time - the present arrangement allows both, but I thnk that we could live with this as we only heat the radiators very occasionally when moored, preferring the stove when longer periods of warmth are required.

 

True

 

No, motorised valves are either one or both.

[dor]

I spent quite a long time looking for a 12V motorised valve to to what you want. The only ones I found were very expensive.

 

You don't say which Alde you have. If it is the Comfort then it would be easy to fit a cylinder stat in series with the pump supply to turn the pump off when the water was hot. You would need an override switch so that you could run the pump when you had diverted to rads if the cylinder was hot. THe Alde Comfort is basically controlled by the pump so it won't interfere with the running of the heater. The 3010 is a bit different but should still be possible.

 

A three way valve lets you select HW, CH or both.

[RobinJ]

Standard diverter valves appear to work off 230v, but as we've got an inverter plus a land line when moored, we don't think that this would be a problem although, obviously, a 12v circuit would be a much better idea. The slight disadvantage of the idea is that only one of the two circuits could be open at a time - the present arrangement allows both, but I thnk that we could live with this as we only heat the radiators very occasionally when moored, preferring the stove when longer periods of warmth are required.

 

Has anyone got a setup like the one we're thinking of and/or does what we suggest seem reasonable/workable? Has anyone got any other ideas to save the fumbling around at floor level? In an ideal world I could see benefits in having the two thermostats control the diverter valve as well as the Alde pump. although I suspect that we'd need to use a relay to do this to keep the 12v and 230v circuits separate.

Most three way valves are actually separate from the motor (I had to replace the motor on my central heating one when it burnt out), however, I have not seen a 12V motor, but they should be available.

Logically there is no reason why you cannot fit a normal central heating controller to the system, which would control the valve using the same circuitry as a domestic heating system, however, you really need to obtain a 12V controller or have a mains one modified. I assume the Alde works on 12V even with the thermostat, so a controller would switch the 12V to control the boiler even if the contacts were rated at mains.

I suspect it would also be simple to interconnect the system with the engine, so the hot water was diabled when the engine was running?

 

C

ELA

 

C

EJA

 

This is supposed to demostrate the flow, A is Alde, C is Calorifier, E is Engine. L represents the open valve water heated by the Alde, J represents the closed valve, water can be heated by engine.

 

Could alll this be negated by using non return valves? Not sure what sort of pressure can be created/overcome? May still need a solenoid valve on the return?

[Big COL]

I spent quite a long time looking for a 12V motorised valve to to what you want. The only ones I found were very expensive.

 

You don't say which Alde you have. If it is the Comfort then it would be easy to fit a cylinder stat in series with the pump supply to turn the pump off when the water was hot. You would need an override switch so that you could run the pump when you had diverted to rads if the cylinder was hot. THe Alde Comfort is basically controlled by the pump so it won't interfere with the running of the heater. The 3010 is a bit different but should still be possible.

 

A three way valve lets you select HW, CH or both.

 

Hi Dor

 

How about a relay and two mag valves, with the stat or selector switch controlling the relay? 12v relays and mag valves are easy to get.

Edited August 21, 2008 by Big COL

[Eeyore]

The gate valve in the radiator circuit is under the side of the bed at floor level - luckily the bed pulls out to provide access. The gate valve in the calorifier circuit is near the calorifier and requires the bed to be pulled out and a removable panel at the foot of the bed to be lifted out to gain access to the valve.

 

We were wondering whether we could fit a standard domestic diverter valve in place of the T and the two gate valves to avoid the need to keep pulling the bed out to get to the manual valves. We might leave the gate valves in place in case we only want to drain part of the system. The diverter valve needs to be able to be mounted such that it doesn't lengthen the pipe runs if at all possible. This means that it will be at floor level where access is not the easiest thing.

 

Hi Ray

I quite like automatic systems, but have you looked at making it manual and simple to operate?

How about a 3 port ball valve to replace the "T" piece. They come in two basic external configurations, so you should be able to fit one. They are also available with internals to suit C/H, H/W or BOTH.

Depending on the instalation you couuld either take off the handle and use an extention to the operating spindle, or drill a hole in the end of the handle and use a control cable in order to operate it.

The two gate valves would be retained as balancing valves. When the ball valve is in the "BOTH" position the flow will take the route of least resistance though the shorter calorifier pipework. The H/W gate valve needs to be partialy closed to increase the flow resistance in that circuit, and allow more flow into theC/H circuit. When you find the best position for the valve you can tie the handle in position.

Eeyore

[Big COL]

Hi Ray

I quite like automatic systems, but have you looked at making it manual and simple to operate?

How about a 3 port ball valve to replace the "T" piece. They come in two basic external configurations, so you should be able to fit one. They are also available with internals to suit C/H, H/W or BOTH.

Depending on the instalation you couuld either take off the handle and use an extention to the operating spindle, or drill a hole in the end of the handle and use a control cable in order to operate it.

The two gate valves would be retained as balancing valves. When the ball valve is in the "BOTH" position the flow will take the route of least resistance though the shorter calorifier pipework. The H/W gate valve needs to be partialy closed to increase the flow resistance in that circuit, and allow more flow into theC/H circuit. When you find the best position for the valve you can tie the handle in position.

Eeyore

 

Four mag valves, Two two way switches, two tee fittings and a tank stat, you could make it fully automatic at the flick of a switch. Which will give you the choice in the heating source, either via the engine or the boiler. Added to which you would have the choice of hot water priority or both IE central heating and hot water.

Two 12volt, port/diverter valves would replace the mag valves and tee pieces, and do the same thing, depending on the availability and price.

[Ray]

Progress report

 

Did some scanning of the Interthingy and located a reasonably close supplier of mag valves. Eventually ordered a pair from them and fitted one just before Christmas. It didn't work because it needed a minimum of 0.2Bar before the valve would open.

 

Spoke to supplier again and he has now supplied me with a valve/motor combination that doesn't need a pressurised system to make it work. These valves draw about an amp whereas the earlier ones drew half that amount.

 

Only trouble with the new valves is that they only have a 5.2mm diameter opening through the valve. The supplier says that he doesn't think that this will cause a problem - the rest of the system is in 15mm plastic.

 

I'm a little less sure as 5mm is a lot smaller than 15mm and the Alde's pump isn't that powerful.

 

Whilst I don't doubt that the valves will allow water to pass, I just wonder how much the performance will suffer because of this restriction in the circuit. I was hoping to fit one this weekend but don't fabcy cutting an even greater chunk out of the pipework to accommodaste the new valve if its going to have to come out because the system's performance suffers as a result.

 

What do others think? Can anyone suggest an alternative idea / source of valves that might not be so restrictive?

 

Thanks.

[smileypete]

Hi,

 

There are some 12v motorised ball valves here which aren't toooo expensive:

 

http://www.baytree.co.uk/products/valve.html

 

You might want to double check the voltage on the 3 port version and whether it can cope with a dirty supply* when the engine is running.

 

*quote relevant ISO standard, Gibbo knows what it is.

 

cheers,

Pete.

Edited January 10, 2009 by smileypete

[Ray]

Pete

 

Thanks.

 

That's where I looked originally but was a bit put off by the price. IIRC I spoke to the chap there and he has them in his boat, which tends to support their suitability.

 

The original valves that I got were £38 for the pair including postage. The newer ones are £98 for the pair (incl). Luckily I can get my dosh back from the supplier and I must admit, they've been very good about answering all my silly questions so I'd like to reciprocate by giving them some business..

 

The inference from earlier postings was that suitable valves wouldn't be too expensive and whilst £98 (for two) seems a bit high (compared to the original £38), £85 each seems even higher. but then if I have to pay £85 to avoid impairing the system's performance, I suppose I'll have to.

 

Is that 5mm diameter opening going to impact on the system's performance or am I worrying needlessly?

[smileypete]

Is that 5mm diameter opening going to impact on the system's performance or am I worrying needlessly?

 

Drill a 5mm hole though a couple of cheap 'gate' valves for a try-out?

 

Overall I think it comes down to the old saying 'Good, quick, cheap - pick any two'...

 

cheers,

Pete.

[Tony Brooks]

When we decided to get a boat we planned to cruise occasionally and to spend a lot of weekends on it at our mooring. When we designed the plumbing we worked to the concept that the engine would provide the hot water and an Alde would heat the radiators, completely forgetting that when we're on the mooring we wouldn't really want to run the engine just for hot water.

 

Once we realised our error we modified the plumbing so that the Alde can heat both calorifier and radiators either singularly or both together - the latter's been quite useful with the summer that we're experiencing this year! We put a T in the outlet from the Alde and then put a manual gate valve in each branch from the T so that we could isolate which ever circuit we wanted to. We also put a remote switch to control the Alde's pump when we just wanted to heat the water. The room stat that comes with the Alde controls the heating to the radiators.

 

The gate valve in the radiator circuit is under the side of the bed at floor level - luckily the bed pulls out to provide access. The gate valve in the calorifier circuit is near the calorifier and requires the bed to be pulled out and a removable panel at the foot of the bed to be lifted out to gain access to the valve.

 

At present the gate valve supplying the radiators is shut and the calorifier gate valve open. We usually flick the remote switch to start the Alde's pump and leave this on until we remember to turn it off when we want hot water. As a result we may be overheating the hot water and wasting gas.

 

 

Snip

 

 

Without knowing which Alde you have I think you can put your mind to rest about "overheating the hot water". I am sure both Aldes have an adjustable boiler thermostat that shuts the gas off once the water in the heat exchanger reaches a certain temperature, so as soon as your calorifier is more or less up to the Alde temperature the boiler will shut down until the boiler temperature falls. The it will fire up again for a short while to bring the boiler back up to temperature and so on. I would experiment with the boiler stat setting to obtain the optimum hot water temperature. The Tall Alde is, I understand, optimised to be most efficient at setting 5.

[Ray]

Tony

 

Thanks for the comments.

 

It wasn't so much the Alde (2928?) overheating that now "worries" me, it was more the fact that whether a 5mm maximum valve orifice on 15mm plumbing will reduce the efficiency of the system such that everything takes longer to heat up.

 

Looking through the valve I'd guess that the opening has to be at least 75% smaller than the adjacent pipework, so I fear that it would take 4 times as long to heat up the radiators and the cylinder - don't know the maths.

 

Ray

[Spoons]

Tony

 

Thanks for the comments.

 

It wasn't so much the Alde (2928?) overheating that now "worries" me, it was more the fact that whether a 5mm maximum valve orifice on 15mm plumbing will reduce the efficiency of the system such that everything takes longer to heat up.

 

Looking through the valve I'd guess that the opening has to be at least 75% smaller than the adjacent pipework, so I fear that it would take 4 times as long to heat up the radiators and the cylinder - don't know the maths.

 

Ray

 

I think you will find that although there is a restriction in the valve it is for a very short distance so the pressure through the actual restriction will increase and balance out at the other side. It will make a slight difference but not the four times flow that you are worried about.

 

Spoons

[Ray]

That's re-assuring. I'm still a bit sceptical on the basis that the Alde's pump isn't that strong.

 

I could accept a reduction in performance on the calorifier as that is located next to the boiler but the radiator circuit goes along one side of the boat and back down the other with probably a 140ft total run from boiler back to boiler via the end of the circuit. As the last radiator is in the bedroom and already takes a while to warm up I wouldn't want it to take much lnger, hence my concern.

 

Am I dreaming or did I read somewhere that you can get a more powerful pump for the Alde (possibly from Alde). I wonder if that might be the way to go. Does anyone know?

[blackrose]

We put a T in the outlet from the Alde and then put a manual gate valve in each branch from the T so that we could isolate which ever circuit we wanted to.

 

Not sure if someone's already suggested this, but instead of two isolators, why not use a single L-port valve?

[Ray]

Thanks for the thought.

 

Single valves allow us to heat both circuits if we wish - each circuit has a switch to turn the pump on and the manual valve allow us to have one or both circuits getting heat.

 

The idea of the "non-manual" valves is to save us having to change the manual valves, which are located in slightly awkward positions.

 

I did give the idea of an L shaped valve another consideration yesterday but couldn't decide whether we could live with only one circuit being heated at a time.

 

Part of our problem is that the calorifier doesn't seem to hold heat overnight (even with a non return valve in circuit). Consequently, first thing in the morning we may want a bit of heat to warm the boat and may also need to top up the hot water - we only tend to cruise out of season.

 

Furthermore, we stay on our boat on our moorings a fair bit so we need to both heat the boat and the water at the same time when we first get there and before the heat from the stove kicks in (if we bother to light that).

[bottle]

This may be shooting for the stars but maybe there is a manual 'T' valve available as per the automatic ones on domestic heating systems.

 

Do not know if they are available.

 

Not read all posts just the last two, so if mentioned before, my apologies.

[Ray]

Thanks for that idea.

 

I have considered installing a 240v diverter valve where the two circuits divide from the boiler supply - take out the T junction and slip in the diverter valve (and the inverter's only a couple of feet away as well).

 

However, I was trying to avoid the use of 240v in case we can't use that at any time. I'm also a little loathe to mix 12v - that drives the Alde pump - with 240v - needed to operate the diverter valve as (I think) this would involve the introduction/use of relays to keep both supplies independent.

[Big COL]

Thanks for that idea.

 

I have considered installing a 240v diverter valve where the two circuits divide from the boiler supply - take out the T junction and slip in the diverter valve (and the inverter's only a couple of feet away as well).

 

However, I was trying to avoid the use of 240v in case we can't use that at any time. I'm also a little loathe to mix 12v - that drives the Alde pump - with 240v - needed to operate the diverter valve as (I think) this would involve the introduction/use of relays to keep both supplies independent.

 

 

Ray

 

Have you considered doing this mechanically using a Draton tapstat or by- pass valve. It will still be auto, an you can still set your hot water temperature. This will eliminate all the electrical problems including the tank stat.

[Ray]

Colin

 

That's something I hadn't seen or considered. I assume that you plumb them in the circuit and the stat opens when it thinks it needs hot water. I can see the advantage of the system in not relying on electricity to work. What I don't understand is how, without the electrical circuit driven by the thermostat, you can turn the bolier's pump on and off.

 

Am I missing something obvious.

[Big COL]

Colin

 

That's something I hadn't seen or considered. I assume that you plumb them in the circuit and the stat opens when it thinks it needs hot water. I can see the advantage of the system in not relying on electricity to work. What I don't understand is how, without the electrical circuit driven by the thermostat, you can turn the bolier's pump on and off.

 

Am I missing something obvious.

 

Ray

 

The alde already has its controls, and you are using them, you wanted to automate your system by not having to manualy use gate valves.

This can be done using tap stats and by-pass valves.

[Ray]

Colin

 

It is either late at night or my brain is dying! I can't see how those tap stats work. What makes them open/close?

 

I can understand how the ordinary stats can make the pump turn on and off but how do the tapstats work and where do the by-pass valves come in?

 

Sorry if I'm appearing thick, they're not pieces of equipment that I am acquainted with.

[Big COL]

Colin

 

It is either late at night or my brain is dying! I can't see how those tap stats work. What makes them open/close?

 

I can understand how the ordinary stats can make the pump turn on and off but how do the tapstats work and where do the by-pass valves come in?

 

Sorry if I'm appearing thick, they're not pieces of equipment that I am acquainted with.

 

Ray

 

If you google for drayton tap stats etc you should find some pictures and diagrams for their uses.

 

Very quick description is a valve that you can set a desired temperature to, that is then opened and closed thermally. There is a capillary and phial running from the valve which is attached to whatever calorifier, hot water pipe, that you wish to control.

I have used them with a lot of success for controlling the temperature of a calorifier on a solid fuel boiler system.

When the pre set temperature is reached the valve shuts down one port and opens another allowing the flow to by-pass the calorifier coil.

[Ray]

Colin

 

Many thanks for the explanation. I could see that they might just work with the calorifier, although it might take a while to get the cylinder stat synchronised with the tapstat's stat in order to shut the pump off once the water temperature was high enough.

 

I'm not so sure that using them on the radiator circuit would work as it would be much harder to match the setting of the room stat - perched high on the wall, with the setting of the tapstat, down at floor level, to turn the pump off when the room's are warm enough.

 

I don't want to keep the pump running all the time if I can avoid it because the action of the pump running will keep making the boiler fire, which wastes gas if we don't need the heat.

 

Ray