Ask a plumber/heating ‘engineer’ anything

[acer12]

Protecting attic water tanks and pipes from freezing. What are peoples recommendations.

Did a big job on insulating a 40yo house this year with a result that the attic is now colder (due to roof vents and extra layers of insulation meaning less heat loss from rooms below) so nervous in this weather. Its a peak roof so the tanks are naturally close to the roof. The following has been completed:

- No insulation under the tanks

- Water tanks lagged with the insulation in a black bag product

- Pipes lagged with the foam pipe insulation
--> Understand this is not very effective.

- Fitted a remote temperature monitor that reports to an app so good to be able to check the temperature.

- Fitted a lightbulb heater over the pipes which is triggered by a temperature gauge.
-> Believe these are limited in use, high on electricity and even a fire hazzard so also have this plugged into a wifi plug so I only switch on during very cold nights!

- Also fitted a spare camera so I can have a look if needed on my phone.

Is spray foaming the roof from the inside a good idea, have heard mixed reviews.

[Harpoon]

B'stard Child said:

You don't pump hot for the whole house do you? I thought it just fed a shower/bathroom

Their concerns are probably around back feeding cold mains to HW tank or pump pressure being higher than mains and pushing water back out into the mains feed - water companies don't like that much.

I have gravity HW feed to a mixer tap in the sink and mains to the cold side and I've actually used that to my advantage when I air locked the HW feed to the kitchen after a HW Tank change

I took the aerator on the spout of a mixer tap and blocking the end and opened both hot and cold taps, forcing mains pressure water back up the Hot feed created enough of a plug of water going upstairs to act as a syphon (when the cold tap was closed and hot tap left open) and clear the air lock

Not at present - pump is only for the upstairs bathroom. My idea was to pump all HW though, otherwise we need a pump under the kitchen and utility sink. Which would have the same potential problem as just using the pump upstairs?

[shtu]

acer12 said:

Is spray foaming the roof from the inside a good idea?

No.

[dhutch]

acer12 said:

Is spray foaming the roof from the inside a good idea.

No. I think would be the resounding vote!

[B'stard Child]

dhutch said:

acer12 said:

Is spray foaming the roof from the inside a good idea.

No. I think would be the resounding vote!

^ This x1000

The problem comes if you sell the property - mortgage companies don’t like it because it can cause the roof trusses to rot as they are no longer able to dry out if they get damp/wet

You only find out you have a problem when the roof collapses..,,.

Removing it is also bloody difficult

[Grey_Area]

We have a Y plan system, boiler operates in heat mode essentially. It's a vented system with hot water cylinder.
Are there any benefits to moving to a S plan system, other than being able to run the boiler at different temps for the H/W and C/H.
TIA.

[Lincsls1]

Grey_Area said:

We have a Y plan system, boiler operates in heat mode essentially. It's a vented system with hot water cylinder.
Are there any benefits to moving to a S plan system, other than being able to run the boiler at different temps for the H/W and C/H.
TIA.

S plans are typically used on bigger systems otherwise no advantage.
And you cannot run the boiler at different temps for the HW and Heating anymore than you cannot on a Y plan.
Not without constant manual intervention anyway.

[Trustmeimadoctor]

Grey_Area said:

We have a Y plan system, boiler operates in heat mode essentially. It's a vented system with hot water cylinder.
Are there any benefits to moving to a S plan system, other than being able to run the boiler at different temps for the H/W and C/H.
TIA.

You want x plan hot water priority

[Grey_Area]

Trustmeimadoctor said:

Grey_Area said:

We have a Y plan system, boiler operates in heat mode essentially. It's a vented system with hot water cylinder.
Are there any benefits to moving to a S plan system, other than being able to run the boiler at different temps for the H/W and C/H.
TIA.

You want x plan hot water priority

I'm not familiar with that kind of setup; I understood our vailant ecotec could do the different temps on an s plan system; so that's all I've explored presently
My plan was to use the VRC controller, with weather temp compensation, and set the H/W to 60 flow, and C/H to about 45-50 flow; rads are all alluminium and about 30% oversized at dt50 according to room size and heat calculations found online.
Just looking for a little more efficiency if I can get it..

Edited by Grey_Area on Tuesday 16th January 19:59

[Lincsls1]

Your system boiler does not differentiate between hot water and heating demand. It simply gets a switched live from either the hot water channel or the heating channel.
The output temperature of your boiler is set on the boiler control panel and is then fixed until you change it. You cannot achieve what you are after with your boiler - X, Y, S plan, whatever.

[B'stard Child]

Grey_Area said:

We have a Y plan system, boiler operates in heat mode essentially. It's a vented system with hot water cylinder.
Are there any benefits to moving to a S plan system, other than being able to run the boiler at different temps for the H/W and C/H.
TIA.

S Plan same as Y plan IMO

Y Plan uses single valve with 3 positions

HW only
HW and CH
CH only

S Plan uses two valves

HW only on one open
CH only on the other open
HW and CH if both are open

I think if you boiler and control system support it both S plan and Y Plan can be configured to run X plan (DHWP Domestic Hot Water Priority) but the kicker is the control system and the boiler have to support it

[Grey_Area]

Lincsls1 said:

Your system boiler does not differentiate between hot water and heating demand. It simply gets a switched live from either the hot water channel or the heating channel.
The output temperature of your boiler is set on the boiler control panel and is then fixed until you change it. You cannot achieve what you are after with your boiler - X, Y, S plan, whatever.

Thanks, boiler has 2 temp controls on the front, labelled C/H and H/W, I'd set these and then forget; unless I needed to refine them for temps.
So, if C/H is in demand it would shoot for say 50 degrees, and if H/W set, it would shoot for 60 degrees, if that's where I set the 2 temp dials; surely?

[Grey_Area]

B'stard Child said:

Grey_Area said:

We have a Y plan system, boiler operates in heat mode essentially. It's a vented system with hot water cylinder.
Are there any benefits to moving to a S plan system, other than being able to run the boiler at different temps for the H/W and C/H.
TIA.

S Plan same as Y plan IMO

Y Plan uses single valve with 3 positions

HW only
HW and CH
CH only

S Plan uses two valves

HW only on one open
CH only on the other open
HW and CH if both are open

I think if you boiler and control system support it both S plan and Y Plan can be configured to run X plan (DHWP Domestic Hot Water Priority) but the kicker is the control system and the boiler have to support it

Ok thanks, bit more reading required on what my boiler is capable of; I know it was capable of open therm control; but only available in mainland Europe using a separate module.
Guess it might get a touch more complicated than my meagre sized cranium can cope with

But I hope not...

Goes off to do some early nighttime reading.

Thanks.

[Lincsls1]

The hot water dial on your boiler is redundant. IIRC, if you adjust it nothing happens or it says on the display 'not applicable' or 'N/A' I can't quite remember.
That dial is simply there for if the control panel was fitted to the combi version of your boiler.

[Grey_Area]

Lincsls1 said:

The hot water dial on your boiler is redundant. IIRC, if you adjust it nothing happens or it says on the display 'not applicable' or 'N/A' I can't quite remember.
That dial is simply there for if the control panel was fitted to the combi version of your boiler.

That makes sense; however it doesn't say N/A or not applicable, but yes I can see if it were a combi how the dials would operate .
Thanks.

[Trustmeimadoctor]

Grey_Area said:

B'stard Child said:

Grey_Area said:

We have a Y plan system, boiler operates in heat mode essentially. It's a vented system with hot water cylinder.
Are there any benefits to moving to a S plan system, other than being able to run the boiler at different temps for the H/W and C/H.
TIA.

S Plan same as Y plan IMO

Y Plan uses single valve with 3 positions

HW only
HW and CH
CH only

S Plan uses two valves

HW only on one open
CH only on the other open
HW and CH if both are open

I think if you boiler and control system support it both S plan and Y Plan can be configured to run X plan (DHWP Domestic Hot Water Priority) but the kicker is the control system and the boiler have to support it

Ok thanks, bit more reading required on what my boiler is capable of; I know it was capable of open therm control; but only available in mainland Europe using a separate module.
Guess it might get a touch more complicated than my meagre sized cranium can cope with

But I hope not...

Goes off to do some early nighttime reading.

Thanks.

Vr33 module I used it in mine

Honestly I'd avoid it and use the vaillant controls

Found this for vaillant dhwp
https://www.urbanplumbers.co.uk/vaillant-eco-tec-p...

[Grey_Area]

Trustmeimadoctor said:

Grey_Area said:

B'stard Child said:

Grey_Area said:

We have a Y plan system, boiler operates in heat mode essentially. It's a vented system with hot water cylinder.
Are there any benefits to moving to a S plan system, other than being able to run the boiler at different temps for the H/W and C/H.
TIA.

S Plan same as Y plan IMO

Y Plan uses single valve with 3 positions

HW only
HW and CH
CH only

S Plan uses two valves

HW only on one open
CH only on the other open
HW and CH if both are open

I think if you boiler and control system support it both S plan and Y Plan can be configured to run X plan (DHWP Domestic Hot Water Priority) but the kicker is the control system and the boiler have to support it

Ok thanks, bit more reading required on what my boiler is capable of; I know it was capable of open therm control; but only available in mainland Europe using a separate module.
Guess it might get a touch more complicated than my meagre sized cranium can cope with

But I hope not...

Goes off to do some early nighttime reading.

Thanks.

Vr33 module I used it in mine

Honestly I'd avoid it and use the vaillant controls

Found this for vaillant dhwp
https://www.urbanplumbers.co.uk/vaillant-eco-tec-p...

Cheers, I've watched some of his YouTube stuff, I think he's quite good.

[B'stard Child]

Trustmeimadoctor said:

Grey_Area said:

B'stard Child said:

Grey_Area said:

We have a Y plan system, boiler operates in heat mode essentially. It's a vented system with hot water cylinder.
Are there any benefits to moving to a S plan system, other than being able to run the boiler at different temps for the H/W and C/H.
TIA.

S Plan same as Y plan IMO

Y Plan uses single valve with 3 positions

HW only
HW and CH
CH only

S Plan uses two valves

HW only on one open
CH only on the other open
HW and CH if both are open

I think if you boiler and control system support it both S plan and Y Plan can be configured to run X plan (DHWP Domestic Hot Water Priority) but the kicker is the control system and the boiler have to support it

Ok thanks, bit more reading required on what my boiler is capable of; I know it was capable of open therm control; but only available in mainland Europe using a separate module.
Guess it might get a touch more complicated than my meagre sized cranium can cope with

But I hope not...

Goes off to do some early nighttime reading.

Thanks.

Vr33 module I used it in mine

Honestly I'd avoid it and use the vaillant controls

Found this for vaillant dhwp
https://www.urbanplumbers.co.uk/vaillant-eco-tec-p...

Spot on - using a Y plan 3 port valve

(from memory Syzmon sets the valve up so it never uses the mid position and at rest is set up for CH only - only when the call for HW is made does the valve switches and moves to the HW position in one of his videos he explains how the wiring works but I think it's simpler to have to valves to make the wiring easier)

Syzmon is really clear on controls - if you've got a Vaillant Boiler use Vaillant controls if you want to maximise efficiency

[Grey_Area]

Thank you all for the guidance, pointers, and very helpful information.

[Harpoon]

Me again Still trying to sort tap flow!

I've now measured flow in litres per minute in the kitchen, utility (both gravity hot and mains cold) and the bathroom (hot and cold both pumped).

The kitchen & utility both have a cold flow of 7.5 to 8.1 lpm, but hot is a dismal 1.8 lpm. In the bath, my 1 litre jug overflowed in sub 6 seconds, so flow is over 12 lpm (hot and cold).

I presume to measure actual pressure and not flow, I'd need something like this?

https://www.screwfix.com/p/monument-tools-mains-wa...

We need an old isolation valve replacing (it leaked into a motorised valve head beneath it and kept tripping the RCD), so I asked the person who came to quote on that work about pumping all hot water from the tank (rather than just the spur to the bathroom). He has said it would cause problems (cold entering the hot feed or vice versa) as the pressures could be different. However, it seems we already have a big difference in pressure which the tap copes with. Non-return valves would stop any hot going back into the mains.

I've also seen pressure reduction valves so couldn't you use these to balance the pressure prior to the tap?

https://www.screwfix.com/p/reliance-valves-predato...

Or I've just found this to equalise the pressure between the feeds:

https://www.bes.co.uk/water-pressure-equalising-va...