Wood boiler Loading Valve Options

[DamianTasmania]

Hi there, I have installed an Esse W35 range cooker, and have linked it to a 250 litre storage cylinder and half a dozen radiators. We are having a lot of trouble with low flue temps, low oven temps and creosote/taring, it is obvious the return temps are putting too much load on the boiler and I am struggling to get it up to working temperature. I figure I need to put a loading valve in the line where I have marked on my diagrams and basically want to know if this is the right thing and place to put it, and if I need a full loading valve or just a mixing valve, an esbe ltc100 or laddomat or just a mixing valve like a esbe vtc300 series as we already have a pump inline.

I have the thermosyphon going to the storage tank which works really well, it will heat the whole tank in a short period and by doing this first before it starts circulating to the radiators, means that the cylinder is ready quicker if you wanted to take a shower.

Any input would be appreciated as it is a great cooker, just really want to get it ready for winter...it is still summer over here.

 

[DamianTasmania]

Here are the layouts for the system at the moment, the first is how it is now, and the second is where I think I should put a mixing valve??

 

[Floydian]

Hello Damian and welcome!

That is a really nice looking stove you have.

I think your mixing valve location looks good but I am not sure your pump is in the right place once you add the mixing valve.

Here is the install instructions for the w35: (broken link removed to http://www.esse.com/support/cookers/installation-instructions/w35_installation_instruction.pdf)

Good luck and I am sure the smart folks here can help you more than I can,

Noah

 

[maple1]

Not sure I understand your storage setup - there's only one line to it? How does water come back from it? Your mixing valve looks more or less in the right place - typically right before your cold returns to the boiler. But also typically (I think), the pump that circulates through it would be located so it is pulling water though the mixer. i.e., it would be between the mixer & the bottom boiler fitting. Others can chime in - and I have no familiarity or knowledge at all of your Esse.

 

[Floydian]

But also typically (I think), the pump that circulates through it would be located so it is pulling water though the mixer.

I agree. I'm just not sure what an "injector tee" is. And the manual shows the tee in between the pump and the boiler.

Noah

 

[DamianTasmania]

Right you are, I have the cylinder and header tank a bit wrong, have updated the pictures to how they are. We queried on the injector tee when we bought it, but the Australian importers werent bringing them in and didnt really know what they are, turns out they dont work too well without one. I figured a laddomat type loading valve would be better but maybe an injector tee is one of these... (broken link removed to http://www.esbe.eu/at/de-de/~/media/ESBE%20PIM_ESBE%20sync%20BR/Documents/Data%20sheets/GB/VTC300_GB_99501362_A_LR.ashx)
They are a lot cheaper than a loading valve and seeing as we have a pump already maybe this is all we need??? We have the pump turning on with a thermostat once the cylinder is heated, but with this valve I could put in a flue thermostat and have it turning on with that... what do people think, would this do the same job or should i just get a loading valve?

 

[maple1]

I think one of those would do the job nicely. I'm not sure exactly what temperature you'd want - typical boiler return protection here is around 140°F. Note the circ pump location in their mixing diagram - I guess that's what I was talking about re. that. Also not sure about overheat protection or if you even need it with that tank way up there - looks to me like the tank would handle that by providing a nice gravity flow buffer. Kind of odd the importers are ignorant on it - it would seem to me to be a key item. Did you try contacting Esse on it? Very nice looking stove BTW!

Also, re. flue temp thermostat & starting the pump. I have one of those to start my loading unit, but on mine the power to the thermostat & pump goes through a Honeywell aquastat first (I think it is a 6006 - not 100% sure on my memory). It has contacts that close one circuit & open another when water temp gets to setpoint. I have the flue temp thermostat wired to the side that opens on rise, and the side that closes on rise is wired straight through to the pump (rough explanation). That way, if the flue temp thermo goes wonkey, the pump will start if the water temp gets up to setpoint (think I have it set for 190°F). I find my flue gas thermo a bit slow to respond sometimes. - if the fire is slow building or doesn't take off good for some reason, the water temp can get up there before the flue gas thermo starts the pump. That all might be moot with the high gravity tank arrangement you have.

 

[Richard Bonnie Doon]

Hey Damian, it's been a long time since this thread was active, but I'll have a punt that you'll have a peek!
I'm a bit north of you in the High Country in Vic, so I guess our situations are similar. Also similar is that I have got a new Esse W35 with half a dozen radiators as well as thermosyphoning to a DHW storage tank on the roof. The latter is also warmed by a solar vacuum tube set up.
I have had a messy start as I did not have the unit you also seemed to need to ensure the Return water was around 55C. I wrote to Pivot Dandenong who suggested a $1000 Boiler Control Unit which looked complicated and would also involve significant re-plumbing. I then found Laddomat 21 mentioned in forums(mainly UK) and they look better the BCU suggested by Pivot and also cheaper.
I'd be interested to hear what you've tried and how it's gone, especially now we're into winter. I've moved back into my shed after the new house set up became so clogged with soot and tar as to be unusable.
Cheers,
Richard