Building Regs and replacing vented cylinder with Heat Bank

[Dan Robinson]

One more time...While a having a Buffer for heating may well be a fine engineering idea, it is not worth doing here. The boiler is Band D but IMHO far from on its last legs yet. You simply need to get the system set up correctly and balanced. You may by all means combine the feed and vent to prevent air ingress and over pumping.


Oh and DD - Condensing is the last thing this boiler needs. But then you knew that already didn't you It won't short cycle if it is set up correctly; but it will cycle like all boilers do on a conventional system. Its called heat loss.

 

[SumoAl]

A Grundfos CI body 15/60 would be about as much use as a Chocolate Teapot pumping salt water! I wouldn't even ask the bronze-body equivalent to do that job. I reckon the iron one would run its bearing in about a week, the bronze one might last a couple of months!

ah, sorry, I keep dropping comments in which I really shouldn't do.

You can get a conversion kit for the Grundfos 15-50 and 15-60 which replaces the impeller housing and the impeller with a marine safe version, so just using the motor drive from the Grundfos and not any of the wet bits.

I'm not actually going to use it for that anyway now as it's actually quite inefficient as a pump, far less efficient than some of the good marine pumps you can get. A bit of money spent on a proper pump will repay in very little time.

 

[Balenza]

Sumoal wrote

I'm not actually going to use it for that anyway now as it's actually quite inefficient as a pump,

Really ?

far less efficient than some of the good marine pumps you can get.

I doubt it.

 

[SumoAl]

Sumoal wrote

I'm not actually going to use it for that anyway now as it's actually quite inefficient as a pump,

Really ?

far less efficient than some of the good marine pumps you can get.

I doubt it.

The new Grundfos pumps with permanent magnets etc are getting there, but pumps aimed at marine aquarium are very good on the joules (watt second) per litre pumped ratio, the older grundfos pumps are not as good. Marine pumps are not cheap though in comparison to circulators like the 15-50, but then we are talking about a pump rather than a circulator, they give out at anything more than a metre or two of head but will pump a high volume at that low pressure.

Grundfos energy rating it's new pumps, the 15-50 gets a C rating, the 15-60 gets a D rating where the Alpha+ gets a B and the Alpha Pro gets an A. The synical side of me thinks they wanted the energy rating just to sell a whole new family of pumps!

 

[Balenza]

SumoAl wrote

they give out at anything more than a metre or two of head

That makes your marine pumps less efficient in my book.

 

[Doctor Drivel]

One more time...While a having a Buffer for heating may well be a fine engineering idea, it is not worth doing here. The boiler is Band D but IMHO far from on its last legs yet. You simply need to get the system set up correctly and balanced. You may by all means combine the feed and vent to prevent air ingress and over pumping.


Oh and DD - Condensing is the last thing this boiler needs. But then you knew that already didn't you

Yes I did. I was speaking "generally".

It won't short cycle if it is set up correctly; but it will cycle like all boilers do on a conventional system. Its called heat loss.

It WILL short cycle unless a buffer is used.

 

[Dan Robinson]

DD - please stop now, its getting cringe worthy.

 

[Doctor Drivel]

DD - please stop now, its getting cringe worthy.

You are right - I cringe a lot....a lot.

 

[SumoAl]

Well, BG have been and replaced the PCB and it fired up ok yesterday evening and this morning without cutting out. I'll give it a few more days to settle in before thinking that they may have fixed it.

It worked for about a month ok last time they "fixed" it. They may be back before then though as it's starting to bang again, the steam train sound never did stop.

Do BG ever cut their losses and send someone to have a proper look at the system or do they just keep on replacing bits that have no effect and hoping for the best?

 

[croydoncorgi]

Hmmmm, as I said before

Sorry to point this out, and never mind about BG's diagnostic skills and repair techniques, but based on your latest remark about lockouts and flashing warning lights, my strong suspicion is that ALL that is (and was?) wrong with the boiler is flow below specified minimum. BG can change the rest of it too, if they want, but IF that's the problem and it's not resolved, the other symptoms won't go away!

Nothing much has changed!

 

[SumoAl]

Just for interest (well, at least mine anyway) BG have been back as the boiler was still overheating. They recognise that it's kettling constantly but don't agree with my local plumber that the pumps on it's way out.

I've rebalanced the system sacrificing the dining room and kitchen and the system has been responding much better in the last few days.

Still banging away and sounding like a steam train though, but not as bad as it was.

Problems appear to have been down to trying to balance the system, and it appears that the pipes going to the dining room/kitchen are very restricted. They are the pipe that is layed in the solid concrete floor rather than under the suspended floor in the rest of the house. Long term solution looks like it may involve digging away at the floor to sort out the pipes.