Has our plumber put us in danger?

[vexation]

Really depends what you asked your plumber to do. If only a boiler change, then perhaps he has done that adequately. But if it comes to 'sorting' the problems on existing as well for the same price, that then is a different ballgame.

The definition of "only" (as in "only a boiler change") would seem to be crucial here . Since the boiler change, the noises from the system are just plain silly. From my perspective the responsibility must be with the engineer and his company to leave it in a reasonable state. They inspected the old system and prescribed the work that's been carried out. The old system didn't have this problem so it seems reasonable to assume that the problem has been introduced with the new work - or is an overlooked consequence of the new work.

Thinking about this, isn't it probable that the heat exchanger in the old boiler would have been more restrictive to flow than the new one? I've still got a hunch that the inertia of the pump stopping/starting is causing the problem -- more flow would generate more inertia wouldn't it?

Looking at the picture, plumbing 'seems' to be correct. Jacking up the F+E cistern may be to 'correct' plumbing run on the F+E pipe which has resulted in expansion pipe dipping into the water.

I seriously doubt that "correcting the run" was the motive. If it had been, chopping a couple of inches out of the vertical would have been the way to do it. On closer inspection the strain this has put on the feed pipe has caused it to leak where it enters the tank

 

[Shift]

forgot to add quote

 

[Shift]

Well jacking up the f+e tank with plastic bottles tells me one thing"bodger" . Hope you haven't paid him yet.

Mibbies the guy was only trying something temporarily to see if it worked....

maybe but even if it is temporary the bottles have almost been squashed flat by the weight, surely there must of been some thing more solid knocking about. As an engineer myself there are some things you don't do no matter how temporary, but everyone has different standards.

 

[Agile]

Going back to the pipework picture, my immediate concern is that there is nowhere shown for air to be expelled from the three port valve which is configured as the highest part of the system in that location.

I cannot see all the rest with sufficient clarity to comment but thats a start!

Tony

 

[vexation]

Going back to the pipework picture, my immediate concern is that there is nowhere shown for air to be expelled from the three port valve which is configured as the highest part of the system in that location.

I cannot see all the rest with sufficient clarity to comment but thats a start!

Tony

Good spot Tony. There is actually an automatic valve on the right, at the same level as the upper connection to the HW Cyl. (forgot to sketch it in). Not sure it works though.

I just pulled a panel off inside a cupboard that was hiding the pipework for two rads on the ground floor. The layout was just as wonky as in the airing cupboard. Localised high points in several places. Apart from the obvious potential for trapping air, what consequences or other effects do localised highs have?

 

[vexation]

Return visit today, another engineer with lots to grumble about over the "jacked up F&E job". This one dropped it back down to free the vent pipe and left with Sentinel X400 (sludge disperser) in the system.

Apparently, the theory behind filling with X400 is to flush out residual cleaner that went in before the power flush. They think the flush didn't get it all out (which would amaze me given the amount of time they spent doing it) so this is going to be left in until the end of the week and then drained and refilled with X100.

Trouble is, I just went up in the loft and got the missus to switch the pump off and on..... at switch-off a jet of water comes out the vent pipe, and at switch-on it sucks like crazy. If it's symmetrical, then I can only assume that the suck pulls in air. Quite how X400 is supposed to fix the over-pumping (if that's what it's called) escapes me.

 

[giblets]

The height of the "up & over" return loop of the vent pipe should be a minimum of 450mm above the water level in the F&E cistern but, in some cases, may need to be higher.

Sounds to me as if the 15mm cold feed pipe is partially blocked causing the pump suction to pull down the vent pipe. No amount of powerflushing or X400 will clear this problem. If you have a small, strong magnet try running it down the cold feed pipework to where it connects into the flow pipe. If it is felt to "stick" then that's were the blockage may well be.

IMO there is also far too much water in the F&E cistern.

 

[tonybhoy]

maybe but even if it is temporary the bottles have almost been squashed flat by the weight, surely there must of been some thing more solid knocking about. As an engineer myself there are some things you don't do no matter how temporary, but everyone has different standards.

Simply trying to give the guy the benefit of the doubt. Very easy to hang draw and quarter someone on the basis of a photo on an internet forum.

Would I have gone out and bought a ply-wood based and CLS to try something? Nope.

I wouldn't have tried what he did but there you go.

Doesn't look good I'll give you that but clearly the guy was struggling and we've all been there. I certainly have.

 

[Agile]

Apparently, the theory behind filling with X400 is to flush out residual cleaner that went in before the power flush. They think the flush didn't get it all out (which would amaze me given the amount of time they spent doing it) so this is going to be left in until the end of the week and then drained and refilled with X100.

This guy seems to be pretty inadequate if he thinks that X400 will have much effect in a week! It needs four weeks!

To do the job quickly he should have used X800 which works in about one day.

He has probably has never heard of X800. Its only been around for about 6 years!

It makes me embarassed to hear of these stories.

Tony

 

[spacethegas]

have a look at giblets post.

a surge arrester may be in order.

 

[shambolic]

Sounds like the news boiler being condensing will have a low water content hex creating more restriction and flow through it causing the system to pump over as the circulation through the boiler is slowed down.

 

[shambolic]

Looking at drawing should he not just tie cold feed into open vent above where it catches in to system. Creating a "sort of" close proximity instal for low head instalations??

 

[vexation]

Sounds like the news boiler being condensing will have a low water content hex creating more restriction and flow through it causing the system to pump over as the circulation through the boiler is slowed down.

More restriction in the new boiler? Hadn't expected to hear that. But isn't pumping-over a sign of excess positive pressure? I thought my vent was located at the nuetral point between the feed and the return side of the pump. Also, the gush of water out of the vent only happens when the pump stops. This jives with my notion about the inertia of a moving mass of water.

 

[Agile]

The feed and vent pipes are connected so close together that its expected they will be at virtually the same pressure.

As giblets says above its possible the feed pipe is mostly blocked.

Certainly there is a problem which should be addressed!

Tony

 

[vexation]

The feed and vent pipes are connected so close together that its expected they will be at virtually the same pressure.

As giblets says above its possible the feed pipe is mostly blocked.

Certainly there is a problem which should be addressed!

Tony

I did a thorough check with a very powerful magnet but couldn't pick up any hint of ferrous blockage (as described elsewhere on these forums). Also, when the feed and vent pipe were swapped to their correct positions, the pipe was dismantled and renewed in that critical region where scale apparently builds up.

The flow through the HW cylinder appears to be good, and all rads heat up quickly and evenly. The only "feature" of the installation that I can identify as being less than textbook is the lack of attention to giving horizontal runs an incline in the direction of flow. Even the feed into the boiler has a slight dip on the way in.