Filling Loop

[Matt_85]

Good Afternoon Folks

Had a plumber over yesterday to inspect why our tun dish had fluid going through it and after being unable to do so, asked that I "keep an eye on it" .... System has a service with a different company next week so they will do more thorough checks I hope.

Anyway, point of the post was to ask this:

The plumber pointed out that the boiler thats on our ground floor (with integral pressure gauge) has no filling loop. Instead the filling loop (Which has been left attached at both ends since we moved in Jan 2020) is in the unvented tank cupboard on the first floor, some 10m away (Straight line). Inside this cupboard however there is no pressure gauges.

He was therefore asking me how I intend to ever re-pressure my boiler given that the only pressure gauge & the filling loop are on alternative floors.

Basically a two man job or many trips up & down stairs.

Against regs ? or just **** installation?

The home builder says its not a defect and was part of their specification.

Comical however is that this plumber also works for the company who did the original install.

Thanks

 

[CBW]

Seen it quite a few times, lazy bad practice is a lot of the reasoning, however, it should be done right from a new build . Unless there’s a pressure gauge in the cylinder cupboard, I would argue that it is a defect.

 

[Madrab]

There should be a red expansion vessel at the same location and that should have the pressure gauge on it, that's an industry standard practice.

Even if it's not part of their 'specification' you'd have to be a real numpty to install that and not think, hmmm, I'd better flag that up and get the spec changed so there's a gauge where the loop is!!

I'd threaten them with ridicule on every media and professional site you can find, if they're not prepared to sort it.

Oh and did you check that the chap was qualified to work on the unvented, ask for his ID. If he doesn't know what's causing it, he shouldn't be looking at it in the first place!!

 

[Matt_85]

Thanks for the replies guys.

We dont have a red expansion vessel at all, if they are any different to a white one ?.

We have a white one above the unvented tank that says "Charge 3.5 bar" on it & not much else. Certainly no gauge on it or anywhere else in this cupboard.

Is there any standard or NHBC guidance that would state a pressure gauge should be present near the filling loop?

Plumbers ID wise, as the homes under the 2 year warranty still, I rang the builder & they arranged the plumber who are also the original installers. I doubt my partner will have asked to see his ID.

 

[Madrab]

You must have a system boiler then, that contains the Expansion Vessel (EV) and pump. Do you know what boiler you have? Sheer madness then to put the loop in the cupboard, it should be near the boiler in that scenario. It really is Central heating 101.

 

[Matt_85]

I would assume it's a system boiler.

The amount of piping is way less than our previous homes combi.

Without being infront of it to have a look, from memory it only has 3 pipes that are all 22mm (water in, water out, gas in?) then one smaller one for condensate?

 

[ianmcd]

Red expansion vessel is for your primary water (radiators and boiler) the white expansion vessel is for the unvented HW cylinder, the two waters never meet

 

[Matt_85]

Ahh, yea that must be inside the boiler then because it's nowhere to be seen anywhere else.

 

[ianmcd]

what make and model is the boiler ?

 

[Matt_85]

Update to this, things got somewhat bizzare.

So a week after the tundish started letting off cold water (And still unconfirmed why) a second leak started.

The unvented tank started weeping water out of the upper immersion heater socket. A baxi tech came out and tried a replacement seal in the hopes that would stop it, however it was identified that it was weeping from the actual fabricated tank rather than the plug.

As the tank itself had a 30 year warranty and failed under 2, it was naturally replaced quickly with a new one. That was fitted today & ive come home to find that the new expansion vessel provided has not been fitted, nor has either of the pressure relief valves or the regulator been replaced & no paperwork been left to say any of these original parts still in use were OK to continue.

After a short phonecall, Baxi believe the problem has been resolved though I did point out that whilst the weeping tank has been rectified, the root cause of the tundish letting off cold water & potentially the cause of the tanks failure has not had any attention.

Lost for words on where to go next with this. 5 plumbers have attended so far and none of them can even suggest an idea why the PRV, statically set at 3.5bar would let cold water past and pop the 6 bar relief valve.

Im no plumber but still a mechanical engineer so naturally this is doing my head in & I cannot figure out why even with a busted expansion vessel (if it was that), how the pressure relief would be triggered over 6 bar if the incoming supply is never been seen to go higher than 5 bar.

And if the PRV was letting water get past at higher pressures than desired, surely my taps upstairs would be noticeably stronger.

My worry now is theyve fitted a new cylinder and within a few weeks time its going to pop again as the root cause is still there.