Two waters for HX (soft for steam, tasty for coffee) - will it work?

Doram

I’m picking up here on an idea that floated in the “Why is Tesco Ashbeck water not ideal” thread:

I am wondering if there is a benefit in using two different waters for an HX machine: softer for the main/steam part of the boiler, more alkalinity for the HX/coffee part (this might be relevant for dual boiler as well - I don’t know because I don’t have one)

This is easy for me to do: after draining the boiler (I do this once every three weeks) I can fill it with soft water (e.g. Ashbeck, or RO water for those who have it). Once the boiler is full, I can move to use water with more alkalinity (e.g. Ashbeck + bicarb of soda, or Lockhills, or remineraliser RO water for those who have it).

Surely as steam is drawn the steam part of the HX boiler will refill as needed with the harder water, but theoretically starting with a boiler full of softer water should help to keep scale down?

But - as the harder water will now go to the group, pipes, valves of the machine etc. - I am not sure if there is any benefit to this approach or not. What do you think @DavecUK, @MWJB, @Rob1 (and anyone else who knows or has an opinion :)).

DavecUK

Doram

I would think it’s best to avoid water that will scale, solenoids 1 way valves etc.. can all be a real PITA to sort. A few mornings ago I came to my espresso machine in the morning, the tank was fuller than it should have been and there was a hell of a void in the brew boiler, not enough to pop the element, but I’m glad I didn’t leave it unused any longer. The cause, some dirt in the 1 way valve, but it could have just as easily been scale, and they can scale literally in months.

Your approach will reduce the scaling problem and on a vibration pump machine the pump itself acts as a valve (sometimes as an extra valve)…but it sounds like a lot to remember and there is still some potential for problems.

LMSC

Doram refill as needed with the harder water,
.
I do not understand why you want to fill / refill with hard / harder water.

When you say harder waters, is it the tap water or the re-mineralised (sodium / potassium bicarb)?
Are you going refresh with the boiler thru the reservoir or open the top of the boiler, get the water out and inject fresh Ashbeck through a large syringe?
Depending on your definition of harder water, the pipes, etc may get scales quickly
IMO, you are going to use Rob’s way of minimising the risk of scaling and make your coffee simple. It works for him. You can see it will work for you

Edit:

You have already answered some of the doubts, I have raised.

logjames

Doram I’ve been using that technique for nearly a year. Once a month, I purge the steam boiler in my MaraX, through the water tap, and refill with distilled water. The residual water left in the boiler provides enough minerals to the distilled water so the level probe still works. I run tap water here, which is approximately 120-130ppm hardness through a charcoal filter, and the 70l resin filter from Lelit, which I recharge weekly using a salt water bath. I try to monitor any scale build-up by checking the mushroom when I grease the cam and the water tap when I drain the boiler.

I don’t think this solution is 100% scale free, but I haven’t noticed any build-up in the areas I’ve mentioned.

Doram

DavecUK I would think it’s best to avoid water that will scale, solenoids 1 way valves etc.. can all be a real PITA to sort. A few mornings ago I came to my espresso machine in the morning, the tank was fuller than it should have been and there was a hell of a void in the brew boiler, not enough to pop the element, but I’m glad I didn’t leave it unused any longer. The cause, some dirt in the 1 way valve, but it could have just as easily been scale, and they can scale literally in months.

Your approach will reduce the scaling problem and on a vibration pump machine the pump itself acts as a valve (sometimes as an extra valve)…but it sounds like a lot to remember and there is still some potential for problems.

Just to clarify: I am not thinking of recklessly using hard water (e.g. tap water) for the HX. I am thinking of using water that has just a little more alkalinity for taste (and that therefore might scale a little), and mitigating that risk by first filling the main part of the boiler with softer water.

Doram

LMSC When you say harder waters, is it the tap water or the re-mineralised (sodium / potassium bicarb)?
Are you going refresh with the boiler thru the reservoir or open the top of the boiler, get the water out and inject fresh Ashbeck through a large syringe?
Depending on your definition of harder water, the pipes, etc may get scales quickly
IMO, you are going to use Rob’s way of minimising the risk of scaling and make your coffee simple. It works for him. You can see it will work for you.

As I said above, I am not thinking of recklessly using hard water. I am thinking of very soft (say Ashbeck) for steam, then remineralised (say Ashbeck + bicarb) for the HX.
I am thinking to refresh the water by draining the boiler via the hot water tap, then refreshing by filling the tank with soft water and filling the boiler from it with the pump as normal. No opening of the boiler involved.

The question is if there is any benefit in doing the above in term of scaling risk, as the remineralised water will still be circulated in the pipes, valves and group?

MediumRoastSteam

The Rancilio Silvia Pro has two independent circuits, with independent pumps. The DIY enthusiasts could make a modification to have a partition in the tank and have two different grades of water.

CoyoteOldMan

MediumRoastSteam I was just thinking of that (two pumps, two tanks), but then I realised that the single pump would also work with two tanks as long as another three-way solenoid is used before the pump (the pump and the solenoid may scale, but unlikely, since they would only get cold water). No need to change the logic of anything: when the brewing boiler requests a refill, the two solenoids (before and after the pump) connect the “brew water tank” to the boiler, and similarly when there is a request from the service boiler.

I may play with that… once my warranty expires!

Rob1

Doram I don’t have DI water. I have Ashbeck (for now). 2. My boiler is stainless steel, so I think I have no problem. Please correct me if I’m wrong.

The chlorides are not good for stainless steel of any grade, especially if scale is involved. How long it takes for it to be a problem is anyone’s guess. How long you’ll get before Ashbeck starts to form scale is another guess - you’ll be feeding the boiler with the remineralised water so I think it’ll happen quite quickly. Probably not worth the effort.

MediumRoastSteam The Rancilio Silvia Pro has two independent circuits, with independent pumps. The DIY enthusiasts could make a modification to have a partition in the tank and have two different grades of water.

Makes perfect sense with two water tanks. I don’t know why more machines don’t have this functionality, I guess because it’s not something people want so it’s not something they bother with.

Doram The question is if there is any benefit in doing the above in term of scaling risk, as the remineralised water will still be circulated in the pipes, valves and group?

You’ll either get scale or you won’t. You can determine whether the water will scale or not in your boiler and in your HX quite easily, using the hardness, alkalinity and temperature. Does the HX temp equal the boiler temp sometimes? If it does there’s no point…if not then you can figure it out based on whatever temp it does reach.

LMSC

Doram if there is any benefit in doing the above in term of scaling risk, as the remineralised water will still be circulated in the pipes, valves and group

Regular refresh means you are not allowing the water that gets additional minerals from steam settle on the boiler. So, you are minimising the risk of scaling.
This is similar to we drawing a small cup of water from the steam boiler after every steam. We will be drawing more water out and more re-mineralised water gets re-filled continuously at our home vs your approach.
Please do test regularly.

Hope they make sense! 😊

LMSC

Given the frequency of refreshing the boiler with Ashbeck, please check if the approach is cost effective versus, for example, Zero Water Jug.

I am consciously not recommending RO — Skuma or Osmio — as they involve an initial outlay. which is worth every penny for some of us. It may not suit every one for cost reasons.

Some of the members logic is simple. We spend thousands on machines, grinder and coffee beans. The water is the most critical element and must be given as much importance as anything else. Please take the approach that you are most comfortable with but aim to keep a simple workflow with the water. 😊

Doram

LMSC Given the frequency of refreshing the boiler with Ashbeck, please check if the approach is cost effective versus, for example, Zero Water Jug.

I am consciously not recommending RO — Skuma or Osmio — as they involve an initial outlay. which is worth every penny for some of us. It may not suit every one for cost reasons.

Some of the members logic is simple. We spend thousands on machines, grinder and coffee beans. The water is the most critical and must be given as much importance as anything else. Please take the approach that you are most comfortable with but aim to keep a simple workflow with the water. 😊

I am asking about the principal, not specific water. If the principal works, it can be done with any soft water for the steam part, and any remineralised water for the HX. For now I am refreshing once every 3 weeks, but I can change the frequency, or the water I use.

Cost of water vs all the rest of the equipment/beans etc. is an interesting question, but maybe we should leave it for a different thread?

dutchy101

LMSC This is similar to we drawing a small cup of water from the steam boiler after every steam. We will be drawing more water out and more re-mineralised water gets re-filled continuously at our home vs your approach.

In addition to drawing the cup of water, do you also flush out the service boiler at intervals?

CoyoteOldMan

Yes, it would work. @Rob1 does this on his dual boiler machine. The question - as always - is cost-benefit.

The main cost is (the amount of) faff that is involved with emptying the boiler. If you do that anyway… pretty much zero.

The benefit depends on how much you use steam. Also, consider that - depending on the boiler’s material - pure DI water can become corrosive for your boiler (as it absorbs CO₂ from air and it turns acidic). Again, nothing that a bit of bicarbonate can’t sort out, but then that increases the faff…

Doram

CoyoteOldMan The main cost is (the amount of) faff that is involved with emptying the boiler. If you do that anyway… pretty much zero.

As you say - I do it anyway. It’s zero effort for me to first fill the boiler with pure Ashbeck before using Ashbeck + bicarb thereafter.

CoyoteOldMan , consider that - depending on the boiler’s material - pure DI water can become corrosive for your boiler (as it absorbs CO2 from air and it turns acidic). Again, nothing that a bit of bicarbonate can’t sort out, but then that increases the faff…

I don’t have DI water. I have Ashbeck (for now). 2. My boiler is stainless steel, so I think I have no problem. Please correct me if I’m wrong.

CoyoteOldMan

Doram I don’t have DI water. I have Ashbeck (for now). 2. My boiler is stainless steal, so I think I have no problem. Please correct me if I’m wrong.

You are not wrong, but this thread will be here and read by others long after we finish discussing. 😉

LMSC

dutchy101 Yes! Not at a frequency of @Doram and Rob. Once in 3-4 months through a drain valve. It is not required at all and I am thinking of making it once in 6 months.

Please see here.

Cuprajake

Lot of fannyig about isn’t it.

It’s why I don’t use water that scales, I may take a tiny hit on taste, but compared to ripping a machine apart to descale it, it’s a hit I’ll take.

dutchy101

Lol Cuprajake it certainly is.

SkumaWater

[unknown] I’d like to send you a sample of our Coffee Balance water. Can you share with me your address by email at alex@skumawater.com ?

CoyoteOldMan

SkumaWater The forum software has been updated over the weekend, which is causing problems… such as your post coming out as addressed to “Unknown”.

Could you please repost who the request is addressed to?