Kentish RenoExtension

I only run mine at 1 bar, but the PRV is still 3 bar  Everything will take 3 bar, so is that wrong?

16 hours ago, PeterW said:

https://www.advancedwater.co.uk/prod-660-468-0732.html
 

1.5bar PRV

Thanks! Not sure why I didn't find any earlier as there are a few on ebay (dubious quality perhaps, but bought an Italian-made one). Guess there's not enough demand to buy them from TS/SF.

 

Next question - is there a max distance I can have the expansion vessel from the return leg? I'd like to have it out of the way (yet serviceable). Probably 4m from the return leg (where it splits off by the willis pumps).

 

Sat in my hand at the moment I have a brand new 1.5 bar PRV, but it's a 3/4" one, sent to me in error after I'd ordered a 1/2" one.  Yours for the cost of postage if it's any use (been sat on the shelf above my desk as I haven't had the heart to throw it away...).

6 hours ago, Jeremy Harris said:

Sat in my hand at the moment I have a brand new 1.5 bar PRV, but it's a 3/4" one, sent to me in error after I'd ordered a 1/2" one.  Yours for the cost of postage if it's any use (been sat on the shelf above my desk as I haven't had the heart to throw it away...).

 

Thanks for the offer Jeremy, but I only ordered one 30mins before you'd posted this!! Another item for the MarketPlace?

 

 

More questions:

 

Next question - I've placed the expansion vessel about 3.2m from the return leg where it splits off by the willis heaters (out of the way, yet serviceable). I couldn't find any recommended distances, so presume this distance is okay?

 

22mm plastic (Hep2o) - found some spare, so was going to use this between the manifold and the willis heaters (which are 15mm):

 

MANIFOLD (1")   -->   22MM PLASTIC -->  15MM WILLIS ----> 22MM PLASTIC -->  MANIFOLD (1") 

 

 

Any issues with flow rates? 

 

I'll have some copper on the inlet/outlet sides also.

 

 

 

 

 

 

 

Edited January 16, 2020 by oranjeboom

The Willises should really be vertical.  I personally did and would prefer to do the 22mm to/from the manifolds in copper. 

 

3.2m is fine so long as it is unimpeded

6 hours ago, TerryE said:

The Willises should really be vertical.

Yes, was seeing whether it could be done on their side as was hoping to use space in the already limited cupboard for other items. But will have them assembled vertically then.  Just had the postman deliver them this morning and the instructions imply the same. Will post them up in the blog for others.

 

6 hours ago, TerryE said:

would prefer to do the 22mm to/from the manifolds in copper. 

 

Yes, if this was a permanent heating source, then I would have it in copper too. But most likely now will probably adopt a cheap ASHP in the summer so I only really seeing this being in use until April. It will need to have a few bends in there also, so plastic would help. Would save a bit of time too.

 

Any major issues with part 15mm copper part 22mm plastic then?

 

6 hours ago, TerryE said:

3.2m is fine so long as it is unimpeded

 

Just a couple of bends.

 

3 minutes ago, oranjeboom said:

Any major issues with part 15mm copper part 22mm plastic then?

Nope, crack on 

Cracking on and just loose fitted most bits now, but with the manifold being slightly lower than the top of the willis heaters I could get air trapped in the top pipework (above the heaters). So was thinking to add an automatic air vent like so. Would the experts on here concur?

 

TIA !

Yep - auto vents are your friend here 

Why two heaters? Half the cost if you only use one!?

 

Has anyone looked at the life cycle cost of operating the Willis Heater compared to purchasing and operating an Air Source Heat Pump? I was thinking I'm 62 years old, how many years could I run the Willis heater before I reach the point where it would have been more sensible to buy a ASHP and all the associated kit.

My heat loss figures are greater than most on here, so figured out I would need 2 heaters. They're likely only going to be short-term (but have now plumbed them in with a long-term backup solution) with the view that I will be using an ASHP for my UFH if I can source a cheap (possibly non-MCS installed) one. But it'll be interesting to see how the house performs when I start heating it. Suspect too costly and ASHP will be favoured.

 

So as with most things @Triassic, it would depend on your heat loss figures and setup. You could run them during E7 hrs so that you have heat in the slab in the morning and depending what heat loss you have, that could last a while b4 heat is called for again.

I might just follow your lead and fit a Willis heater in the short term, so as to get some heat into the house. 
 

I’m at first fix stage, so plan to put the pipework and electrics in place for an ASHP.  I’ll fit a non-MSC ASHP, if I can source one at the right price. As with many self builds, money is tight, so let me know if you spot any ASHP bargains! 

 

This is how we set up temporary Willis heaters. 
The 22mm into 22mm tees with 22x15mm reducing sets giving 15mm copper tails to connect the heaters off. 
The 22mm is a constant recirculating loop, with a pump, so the heaters don’t boil or short cycle like crazy. 
At the bottom is the 22mm ‘return’ which was connected to the manifold return and then the top right 22mm after the pump had another tee which becomes flow to the manifold. 
Don’t connect them directly to the manifold as the flow will be proportional and cause headaches. 
Works a treat and we have 2 jobs running on these at the moment, toasty warm. 

Above is a sealed and pressurised kit ( expansion vessel / PRV / fill loop / pressure gauge etc ). 

6 minutes ago, Nickfromwales said:

The 22mm is a constant recirculating loop, with a pump, so the heaters don’t boil or short cycle like crazy. 

Your Hand was in the way! Couldn't see the loop.

 

Where are feed and return?

 

1 - 2 -3 - 4 On

4 -3 - 2 -1 Off      KISS!

Edited January 23, 2020 by Triassic

I notice you are all just putting the willis heaters on a switch.

 

No attempt to interlock this with ensuring the pump is on and water is flowing?

 

The "engineer" in me says contactor controlled by call for heat from manifold controller which in turn is controlled by the room thermostats.

 

Or are you just relying on the immersion thermostat to turn off if the water stops flowing?

54 minutes ago, ProDave said:

I notice you are all just putting the willis heaters on a switch.

 

No attempt to interlock this with ensuring the pump is on and water is flowing?

 

The "engineer" in me says contactor controlled by call for heat from manifold controller which in turn is controlled by the room thermostats.

 

Or are you just relying on the immersion thermostat to turn off if the water stops flowing?

Yup and yup. 
On our permanent installs they’re exactly as you say. Contractor fed so cannot be run dry.   

On the temp setups I’m happy to just explain the 1,2,3,4 process. 

1 hour ago, Triassic said:

Your Hand was in the way! Couldn't see the loop.

 

Where are feed and return?

 

1 - 2 -3 - 4 On

4 -3 - 2 -1 Off      KISS!

Off = 1,2,3,4 

eg turn the heaters off before shutting down the pumps and vice versa. 
KISS at its finest.

2 hours ago, Nickfromwales said:

 

This is how we set up temporary Willis heaters. 
The 22mm into 22mm tees with 22x15mm reducing sets giving 15mm copper tails to connect the heaters off. 
The 22mm is a constant recirculating loop, with a pump, so the heaters don’t boil or short cycle like crazy. 
At the bottom is the 22mm ‘return’ which was connected to the manifold return and then the top right 22mm after the pump had another tee which becomes flow to the manifold. 
Don’t connect them directly to the manifold as the flow will be proportional and cause headaches. 
Works a treat and we have 2 jobs running on these at the moment, toasty warm. 

 

 

Those Willis heaters are mounted upside down!

 

They are supposed to be mounted with the heating element cap at the bottom, so there's no air pocket trapped adjacent to the heating element bit above the side branch.

 

This diagram (randomly nicked from the web) shows how they are supposed to be installed:

 

Looks neat as always @Nickfromwales !!

 

1 hour ago, Jeremy Harris said:

 

Those Willis heaters are mounted upside down!

Yes, that's what the instructions (posted above in blog) seem to state also. But perhaps Nick's setup won't have any air in his plumbing at all! ?

 

My setup so far means I am relying on the manifold pump to circulate the water through the heaters too. They're only a short distance from the manifold on the adjacent wall:

 

Still need to figure out how to connect the pipework to manifold. Was even thinking of using 19mm bore flexi connectors as this is just a short term solution after all. 

Not shown, but will have a 15mm pipe going up (see spare 22x22x15 on return flow) to the expansion vessel.

 

Still loose fitted by the way so hence the dropped pipework in places!

 

I think this photo:

 

 

is either the second or third Willis setup I've seen with the things mounted upside down.  Your set up, @oranjeboom is spot on, and is exactly how they are supposed to be fitted.

 

Fitting them upside down leaves an air pocket in the section above the side (supposed to be the inlet) pipe, which then means that part of the heating element will be running in air, which is not desirable in terms of prolonging the life of the immersion element.

After purging these out  I've seen no argument strong enough to make me put these in the other way around TBH. The prospect of a leak getting down into the electrics is far more of a factor for me than a few mm of air sitting at the head of the heater jacket. The thermostats push in too, so want to drop down / out when the other way around. With faultless operation to date to reflect upon, over multiple instances, I remain sufficiently happy that water leaking down onto electrics vs the air pocket 'issue' ( yet to be shown how much of a real world issue that actually would ever be !?! ) is argument enough for little 'ol me to carry on on my own judgement. I could be convinced to put them horizontally maybe, so I'll reflect and see if there's sufficient merit to do so.

I did look at google images of other installations and decided upon what I thought was the lesser of the two evils.

37 minutes ago, Nickfromwales said:

After purging these out  I've seen no argument strong enough to make me put these in the other way around TBH. The prospect of a leak getting down into the electrics is far more of a factor for me than a few mm of air sitting at the head of the heater jacket. The thermostats push in too, so want to drop down / out when the other way around. With faultless operation to date to reflect upon, over multiple instances, I remain sufficiently happy that water leaking down onto electrics vs the air pocket 'issue' ( yet to be shown how much of a real world issue that actually would ever be !?! ) is argument enough for little 'ol me to carry on on my own judgement. I could be convinced to put them horizontally maybe, so I'll reflect and see if there's sufficient merit to do so.

I did look at google images of other installations and decided upon what I thought was the lesser of the two evils.

 

+'s and -'s for the positioning.

 

I always seem to have plenty of air in my plumbing so wanted to avoid that air pocket at the top.

 

I did also notice that when having the willis 'the right way up' is that copper pipe will slide very nice into the heater at the top....and way down into the chamber itself touching the actual heating element inside. Probably not what you want! Also possible to drop and lose your copper pipe in the chamber - bit of a pig if you've just plumbed in the return pipes at the bottom. Perhaps other willis-type heaters have some sort of retainer to prevent you from over-insertion of the pipes!

 

38 minutes ago, Nickfromwales said:

I did look at google images of other installations and decided upon what I thought was the lesser of the two evils.

 

Reminds me of searching for 'willis heaters' on ebay...don't think it quite understood what kind of heater I was in need of...

 

Edited January 23, 2020 by oranjeboom

Doesn't "On the side, with the side pipe upwards"  solve all the arguments?  No air pockets, thermostat won't drop out, a leak won't soak the electrics.  What is wrong with that?

1 hour ago, ProDave said:

Doesn't "On the side, with the side pipe upwards"  solve all the arguments?  No air pockets, thermostat won't drop out, a leak won't soak the electrics.  What is wrong with that?

Nothing, upon review. ?. 
Im still unconvinced there is any real detriment, unless someone has an instance to recall, to them being as I fitted them. Probably / maybe isn’t argument enough when I see them in and working and if they were airlocked at the top you’d be able to hear it. The ones I have in currently are running perfectly well and silently ( bar the noise of the adjacent pump ).

2 hours ago, Nickfromwales said:

After purging these out  I've seen no argument strong enough to make me put these in the other way around TBH. The prospect of a leak getting down into the electrics is far more of a factor for me than a few mm of air sitting at the head of the heater jacket. The thermostats push in too, so want to drop down / out when the other way around. With faultless operation to date to reflect upon, over multiple instances, I remain sufficiently happy that water leaking down onto electrics vs the air pocket 'issue' ( yet to be shown how much of a real world issue that actually would ever be !?! ) is argument enough for little 'ol me to carry on on my own judgement. I could be convinced to put them horizontally maybe, so I'll reflect and see if there's sufficient merit to do so.

I did look at google images of other installations and decided upon what I thought was the lesser of the two evils.

 

 

Except that mounting them upside down is the opposite of the way they were designed and intended to be used, and air/gas is always going to collect in that space, no matter how much you faff around trying to bleed air out around the immersion threads. 

 

I'm not a fan of fitting things in the opposite orientation to the designer intended, and in the opposite orientation to all the many of these things in use across NI.  Far better to just stick to the original MIs, IMHO.

 

 How many years experience do you have of mounting them upside down and still being reliable?  Willis has decades of experience of them being reliable when mounted in accordance with their original design.

 

 

1 hour ago, ProDave said:

Doesn't "On the side, with the side pipe upwards"  solve all the arguments?  No air pockets, thermostat won't drop out, a leak won't soak the electrics.  What is wrong with that?

 

Yes, with a pump that probably works just fine.  They were originally designed to just thermosyphon, as shown in the top diagram in the first post in the thread specific to this issue, but if pumped should work OK sideways, with the bottom port facing upwards. 

 

I still think it's better to mount them as Willis intended, though, as they've got a pretty good track record for working very well when mounted as designed.

 

8 minutes ago, Nickfromwales said:

Nothing, upon review. ?. 
Im still unconvinced there is any real detriment, unless someone has an instance to recall, to them being as I fitted them. Probably / maybe isn’t argument enough when I see them in and working and if they were airlocked at the top you’d be able to hear it. The ones I have in currently are running perfectly well and silently ( bar the noise of the adjacent pump ).

 

I doubt you'd hear any noise from that big air pocket, as the water is just going to flow undisturbed across to the "inlet" being used as an outlet.