Boiler/heating issue

[Rayniac]

Hi all - this is my first post here (although frequent guest user) - please do let me know if this is not the appropriate place for this topic.

In short - about 10 days ago the central heating pump started making loud humming noise and following attempts to remove any air lock (radiator and pump air bleed) this didn't get resolved. We booked an appointment with a reputable trader to come and take a look and potentially change the pump - this took place yesterday. Until that point in time, everything else in the system worked properly.

The trader installed a new pump, but also decided to change the valves (which I believe is a common approach), leading to complete bleed of the system. Following all that, upon completion of the work the boiler stopped working and we are currently left without central heating and hot water.

The engineer that performed the job arranged for another engineer to come and take a look at the system, which happened a couple of hours later. The second engineer decided to change the motorized valve as it seemed to be working only for hot water and combined settings (not heating only) - this also worked perfectly fine before the pump change since I was actually checking what it does and what the settings were. Following that the boiler still did not work, and the engineer changed the timeswitch without even asking us - to no actual benefit. Then he moved to try and push any air locks out resetting the boiler several times - which did not work.

At the end of the day, the engineer stated that the issue is with the boiler (this is a first) which I do appreciate is quite old (Baxi solo) and that we would need to change. Alternatively we would need to try and push any air locks out by constantly resetting the boiler, although he mentioned that he does not believe this is the issue.

I am not currently certain what the problem is, and if what was carried out was the right set of repairs - I am not in a position to put the blame on the traders as at the end of the day they may be right and the boiler could have started misbehaving. However looking at the facts and what happened, I am quite frustrated that yesterday morning everything was working and we had hot water and heating, while now I am looking at a 3-4k bill without really knowing whly.

Any opinions or experience with this would be much appreciated!

 

[oldbutnotdead]

Best in the heating and plumbing forum- I've reported it & asked for it to be moved.

 

[Rayniac]

Much appreciated!

 

[oldbutnotdead]

While we're waiting- if the bloke who did the pump swap didn't clear the gunge from the f & e tank before draining (I'm assuming a traditional unvented system given the age of the boiler) it's highly likely that there's a blockage somewhere. When you say boiler doesn't work, is it not firing at all or is it just not staying lit for very long?
PS Don't call them engineers, doesn't sound as if they have much of a clue

 

[Rayniac]

To be honest the guys went to the loft where the tanks are so not sure what was done there. It may have been only checks rather than cleaning as it didn't take them a lot of time. We tried to reset the boiler numerous times (reset button placed on the left side of the boiler) - it did not work. Our way of resetting currently is via the boiler thermostat control knob, where we put the dial to zero and then back to 1 or 2 again. This does not always work. Once it does, the boiler fan switches on, then the flame starts 6-7 sec later, and the boiler runs for approx. 1 minute. The pipes above it are getting warm so it looks like it is working but then it cuts out (perhaps overheating if there is a blockage?).

 

[BlueLoo]

Take a picture of the new pump and include a bit if the piping around it
Take a picture of the new valve.
Take a picture of the head tank.

I would suspect the idiots have broken something, fitted something wrong or not opened up the valves.


So, check all the valves are open, the head tank is full and the pump is in the correct orientation.

Horse the pump on full blast for a bit. Check the head tank to see whats going on.
Make sure all rads are well bled.

You should get it firing up!

 

[Rayniac]

I am attaching the pics of:
The new pump
The tank (outside) - we changed the tank approx. 4 years ago as the old one started leaking
The level of the water - looks ok to me but not sure really.

All radiators have been bled out of air numerous times for the last 24 hours and even before hand. No air in the radiators atm.

 

[BlueLoo]

The pump is a new variable speed pump.

Read the instructions.

Make a note of what it is currently set too, and then set it to max-fixed speed.

Run it for 1/2hr.

(Std commission as per the pump IOM).

This should get the system moving.

Then set the pump properly.

It is likely that this will be a fixed speed setting unless your old pump was also variable.

Don't suppose you have the old pump still?

 

[Rayniac]

Thanks a lot for the suggestion - I will try to do this in the late afternoon. I do not have the old pump with me anymore, but I am attaching the image I took a week ago.

 

[Harry Bloomfield]

We booked an appointment with a reputable trader to come and take a look and potentially change the pump - this took place yesterday. Until that point in time, everything else in the system worked properly.

Obviously not that reputable or capable then perhaps? Bodgit and run..

 

[oldbutnotdead]

Well that's a rare treat- a properly installed f & e tank. The blockage due to rubbish from tank scenario is far less likely than I'd originally thought...

 

[oldbutnotdead]

If the 'engineer' changed the timeswitch as well it's highly likely he's wired it up incorrectly- 3 port valves are unfamiliar territory for current day combi slingers. And as above, a reputable company would not leave you without heating and dhw, especially given the minor nature of the initial problem. Dunno how much they charged you but if it was more than the cost of the pump you've been robbed....

 

[Rayniac]

I am attaching the pic of the boiler and (forgive my ignorance) have a couple of questions I am not clear about:
- should both pipes above the boiler be hot? When the boiler starts, the left one is getting hot but I think the right one is just warm and not too hot.
- should the central heating pump be working 100% of the time or only when the boiler starts? The old pump kicked in only when the heating/hot water was being heated.

On the bill - yeah, I did get charged a bit more than the original quote for the pump and valves replacement as a second person came in to see what was wrong and although they didn't fix anything they replaced the (acording to them) now faulty motorized valve and timeswitch (working fine prior to the works being done), spending 2 hours doing that and trying whatever else to get things running.

From what I am hearing, it seems that installing a new boiler would not necessarily resolve the issue - I am ready to get a new one in but only if I am convinced that this will solve the problem.

 

[oldbutnotdead]

Those 2 pipes- one is flow (hot water leaving the boiler to heat rads/hot water), the other is return (cooler water coming back having heated rads/hot water).
With your setup the pump should be running whenever heating or cylinder thermostats are calling for heat. The boiler may cycle on and off (if circulation is poor so it is generating more heat than the system can distribute).
There's very little to go wrong with that boiler of yours and I wouldn't believe a word your 'engineers' said about boiler problems.
You need to start from the beginning. Check the pump valves are open. Check the pump is flowing in the correct direction (same as the old one, if you still have it there'll be an arrow cast into the casing showing flow direction, same with the new one).
Then check that the motorised valve is moving to the correct position when heating or dhw or both are calling for heat. Then check the pump is actually running when heat is called for (either heat or dhw demand). Then worry about the boiler.

 

[Rayniac]

Thanks a lot for this - I did now have a much closer look how the system is designed to work. In any case, here are the updates:
- checked the pump valves - open and as they should be;
- the pump was installed correctly (in terms of direction of the water flow);
- the motorised valve works fine and swithces when I change the settings on the controll panel;
- the pump seems to be working, I left it on for 1 hour at the high speed settnig. It cuts off when the valve switches to different options, then starts immediately when the switch has changed - seems absolutely fine comparing this to what used to happen before;
- I went to reset the boiler and got it fired up, again it worked for 1 minute and then cut off. I specifically checked the pipes above it again, prior to the reset. The left pipe was again very hot - so not sure if this is normal since the boiler was not working for the past 2-3 hours (my understanding is that the water should have been cooled down). Could there be an electrical fault in the boiler perhaps causing constant overheating?
- when I ran the boiler I went upstairs to check if any warm/hot water was getting to the pump - none, the pipe going to the pump (as well as all others) is absolutely cold;
- I noticed that there is a small leak (please see the attached images) - not sure if this is the stopcock or anythin different and not sure if this has anything to do with the problem.