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Gearing Up For A Temporary UFH Buffer


Onoff

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It contains only 2-5 litres of water. 
 

The point of an LLH is to allow different flow levels through different parts of the system, not to act as a buffer store to stop short cycling. Oil boilers don’t modulate down enough to not short cycle at low heat demands. Your boiler is running at 65c pump speed 3, UFH needs 40c pump speed 2, therefore you need somewhere to balance that off hence the buffer. 
 

For an efficient burn on that boiler, and getting you mains pressure hot water, a TS would be my plan as it allows you over time to change out the components and add in whatever you need for heating. You can even blend at the TS itself and negate the need for a manifold blending unit, and your single pipe would still just go in and out of the TS as normal. 

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2 hours ago, PeterW said:

Your boiler is running at 65c pump speed 3, UFH needs 40c pump speed 2, therefore you need somewhere to balance that off hence the buffer. 

 

Boiler at pump speed 2 at the moment. Trying to get the differential up between flow and return.

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Hmmm...SWMBO thinks she saw water coming from the overflow earlier today. First told me it was yesterday! Don't think so luv  the system was still in pieces! ? (Could I suppose have been the CWS...)

 

One overflow visible externally that tees off to the F&E and CWS tanks. So which one was it?

 

Hopefully not the CH pumping over into my nice clean header tank! 

 

Both ball valves recently renewed. 

 

Loft time again!

 

Could it be to do with the fact I've turned the pump down to 2?

 

 

Edited by Onoff
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Up in the loft, balanced on a precarious wooden step ladder that came with the loft! All I can do is hold the phone above the rim at arms length. I can't actually get up there to peer in. 

 

Hoping against hope it's an illusion but that looks like rusty crap in the bottom from a pump over?

 

20201109_165954.thumb.jpg.ad5a0010b3be06f1d39dc3af6b598a6a.jpg

 

Thinking to maybe lower the F&E tank level a tad?

 

20201109_165945.thumb.jpg.783437d7bbcf8fdc335369f07d26b64f.jpg

 

Going to try and get higher on the ladder whilst SWMBO holds the steps. 

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Definitely some rusty crap in the bottom of the F&E tank. 

 

Now this tank was cleaned spotless and had the expansion pipe capped & the feed out turned off when I ran the PFM. So when I refilled the system it was fresh clean water that went into the system. 

 

This must have come up the expansion pipe. Is expansion "normal"? As in does it always happen?

 

Maybe I just need to lower the tank level by adjusting the ball valves?

 

Thanks

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12 minutes ago, PeterW said:

tank only needs 6" water in when cold - just bend the arm.

 

Will do. Trouble is I have to likely take it out to do so. Cramped is an understatement. Very wary too of bringing down the platform that both tanks sit on. Pallet wood sat on 3 cross members nailed to the rafters. 

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Bloody forum putting these new fangled TS ideas into my head! ?

 

I need a plan then, I mean I literally need a plan. If I can find (& finish) this unfinished drawing and show the lounge, rest of the kitchen, position of boiler as is, it might help me visualise things. 

 

IMG_20190728_093421887

 

Got a feeling this was done in Draftsight on an old Linux pc...stuff doesn't transfer well straight to AutoCAD for what I want to do with it. 

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The low volume in the LLH isn’t that relevant. Flow to the manifold pump will be there in abundance as the flow will just ignore ( shoot straight through ) the LLH when it wants ‘full wallop’ and then flow will just simply recirculate ‘through / around’ it when needing nowt / next-to-nowt. 
The CH flow and return will prob be best off running through the LLH instead of being T’d off the single pipe tbh so the premium heated water has to flow through to continue its onward journey. All we need here is hydraulic separation. 
Thinking SP flow into top of LLH, then onwards flow ( aka return ) from lower connection ( same side ), and then flow to manifold pump from top connection other side, manifold return below that. 

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Well after living with the cleaned system for nearly a week it seems we can have the stat down at least 7.5degC and still feel warm. Place seems to warm up quicker and rads are hotter. That being said the boiler still comes on frequently but I guess that's the heat loss via the fabric.

 

I'll bend the float valve in the F&E tank tomorrow to stop it coming out the overflow. Then I'll add the inhibitor.

 

Thanks btw to all who helped.

 

 

Edited by Onoff
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10 minutes ago, PeterW said:

Really pleased this has sorted a few of the issues. Are you pulling the mag filter to see what it’s like and add the inhibitor ..?

 

Is UFH on the cards soon..? A warm bathroom for Mrs Onoff for Christmas 2020..??

 

Don't get your hopes up, she isn't!

 

How often should I be pulling the filter? I pulled it I think 7 times before the power flush and of course it was caked, rotten.

 

Once since. Less crud than all the other times but some. There's obviously a bit (of crud) still in the system judging by what's gone up into the F&E tank. He'll, I'll pull it once a week if it's a good idea.

 

(I'll go pull the mag filter in a minute and post pics). 

 

I was debating whether I could dangle a swarf collector in the F&E tank wrapped in a plastic back and see what it attracts?

 

https://cpc.farnell.com/evolution-powertools/cyclone/cyclone-magnetic-swarf-collector/dp/TL18867?

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15 minutes ago, PeterW said:

Let the mag filter do it - the one I use has a 800 micron stainless gauze filter too that is like a disk of mesh at the bottom of the filter. 

 

Still getting crud out, but to be expected I guess. More black than rusty mind. From what I've read, power flushing of single pipe systems has its limitations even if reversing the flush. Best way is rads off and hose out in the garden. 

 

Unscrewing the lid from the mag filter was a mission. Put a spanner on it in the end and a smear of silicone grease on the threads when it went back on. Not the best light for the photos:

 

IMG_20201113_210216961.thumb.jpg.de0f67084146b7bba5edbda49eea47e3.jpg

 

IMG_20201113_210237287.thumb.jpg.b1b9120fac84982d06173387f7ae38f7.jpg

 

Not happy tbh connecting anything new, like UFH to this.

IMG_20201113_210553812.jpg

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Bent the ball valve arm down a bit in the F&E tank. Hopefully that'll stop it coming out of the overflow.

 

Added the first dose of inhibitor just now.

 

Can I not just add the inhibitor to the F&E tank? 

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13 minutes ago, Onoff said:

Can I not just add the inhibitor to the F&E tank? 


Yes if you drain the contents into the system by venting somewhere else but tbh you won’t have enough flow between the tank and the system apart from when you are filling the system. Just use the magnaclean for what it’s there for !

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39 minutes ago, PeterW said:


Yes if you drain the contents into the system by venting somewhere else but tbh you won’t have enough flow between the tank and the system apart from when you are filling the system. Just use the magnaclean for what it’s there for !

 

Will do ?

 

Amazed at how stiff the mag filter lid is to unscrew, a spanner job. Maybe because I'm doing it hot? I've smeared silicone grease around the threads and is tbh easier.

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4 minutes ago, Onoff said:

 

No, it didn't, definitely not.

 

Interesting comment here ?:

 

https://www.diynot.com/diy/threads/cant-unscrew-intaklean-2-filter-lid.520710/


From memory it is the same as the Flomasta one and you can get spares from S’Fix

 

 https://www.screwfix.com/p/flomasta-magnetic-filter-seal-service-kit/3287V

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