No heat upstairs, cannot locate CH pump, what to do

[Tony]

I'm having trouble getting the upstairs radiators warm, the downstairs ones are fine. I've bled the upstairs radiators but this hasn't made any difference..

I suspect that the pump may be the problem. Unfortunatly I cannot locate the pump, the boiler (Ideal Mexico ) is located in a cupboard in the kitchen, but I dunno where the pump is, I can hear a clicky sound from under the floor close to the boiler,under the kitchen cupboards/worksurface etc. maybe its there.

Anyhows the kitchen was modenised just before we moved in, about 4 years ago and the floor is covered with nice stone tiles, so removing the floorboards to locate the pump is really not an option.I would have to totally remove the cupboards and worksurface also.

Can I add a second pump to the system somewhere to boost the water upstairs and around the cold radiators. If so can someone suggest a pump and where I should place it..

Ofcourse the problem could be something else , but I cannot think of anything else it might be .

Many thanks from a gratefully novice.

Any suggestions gratefully received.

.. Tony

[Set Square]

I can only guess at the reasoning behind your (almost certainly flawed) diagnosis. It requires no more effort from the pump to circulate water upstairs than it does downstairs. The pump doesn't have to provide pressure to lift the water by 3 metres because it is balanced by the return flow coming back down - it only needs to overcome friction losses in the pipes, provided there are no air-locks.

Nevertheless, you'd better find your pump, PDQ! Pumps don't live for ever, and you may need to replace it one day. Are you sure it's not in the airing cupboard?

If it's a vented system, make sure that there's some water in the small F&E tank (not the large cold water header tank) in the attic - and that it hasn't run dry due to a sticking ball valve. Then bleed the upstairs rads again.

If necessary, turn off *all* rads - and then turn each upstairs rad on one at a time to give it a bit of urge. If you can get them hot by doing that, but they then go cold again when you turn the downstairs rads on, your system is in need of balancing - plus you may need to increase the pump speed if it has a speed selector (pretty difficult if you don't know where the bl**dy thing is!)

[Tony]

Many thanks for the reply, I'll do as you suggest and report back , later..

thanks again

.. Tony

[Tony]

Well I've just turned off all the rads in the house and then turned on one in a bedroom, -- no joy , it remained cold, I did check the tank in the attic and it was full..

Any ideas welcome..

.. Tony

[Ed Sirett]

IIRC the pump is inside the boiler case on a Mexico.

The usual cause of upstairs rads failing is

No water (but still enough for downstairs. Rads full of air. Stuck TRVs.

[Tony]

Thanks for the reply Ed,,

I don't have any TRV so its not that, I've gone around and bled all the rads, so its not that... How would I know if " no water " to run the upstairs radiators, the header tank is full and when I bled the rads the air was followed by water, so I assume that the header tank is topping up the system...

Heres a silly question , if it is the pump??, can a second pump be used, can the original pump be electrically disconnected from the controller (Danfoss 103E5 ) and a new pump wired in, in its place, this would assume that the original pump would remain passive open? , is that the case, I not sure how these pumps function.

May be stupid logic , but may also save a lot of cash and almost wrecking our beautiful kitchen..

.. Tony

[Ed Sirett]

Another possibility is that there is a valve to prevent unwanted gravity circulation in the upstairs rads. This may have become stuck.

The pump is likely to be OK if the downstairs rads are working.

-- Ed Sirett - Property maintainer and registered gas fitter. The FAQ for uk.diy is at

Gas fitting FAQ CH FAQ

[Jerry]

In article , Tony writes

You could try lifting floorboards outside of the kitchen area. In a previous property I owned, I had to trace a leak from the heating system that I suspected was under the floorboards. I found that access points had been left in the sleeper walls that gave access to most of the under floor area. Even if there is no access, the sleeper walls are usually honeycomb construction and you can easily knock out a few bricks to get through.

[chris French]

In message , Ed Sirett writes

We have a Mexico, there is an external pump - though it's a few (3-5) years old and of course I don't know what other models there might be.

In our last house the pump was indeed underneath the middle of the kitchen floor.... Damn stupid place for a pump :-) took me while to find it as I couldn't believe it was in such a silly place

OK there was access into the crawl space from the hall way - but it was an awkward shuffle on your back.

[Tony]

Tried everything that I can think of. If I turn off all the rads and then turn one of the upstairs rads on it will heat up OK but if I try to increase the number turned on the the heat is greatly reduced and infact only a few rads get the heat at all, I know it at first seems like a balancing job, but surely an Ideal mexico super 3 60000btu boile can deal with a few rads upstairs..

I live in a 1965 4 bed detached house with 4 doownstairs rads and 6 upstairs rads. open system CH. Measuring the pipe temps on the furthest rad ( single) when turned on by itself gave a reading of inflow=125F , out flow=101Fr both valves set fully opened.

Is it possible to add a 2nd pump to the system to boost the water circulation speed is necessary..

.. Tony

[Nick H]

Tony, just on your pump question.

The pump is simply a circulating pump and as such just pushes the wate around a full system, much like a paddle boat, so it wouldnt be able t draw water up like a fountain pump for instance. Consequently, if th pump isnt running water water will still flow through it so in theor you could add another pump to the system provided the existing pum isnt shut off or blocked

-- Nick H

[John]

IF you are happy that you can balance the system then the problem may lie in the pump or a wide open bypass robbing the radiators of flow

[<me9]

Have you checked the header tank? That's the usual first problem, a sticking ball valve causing the upstairs radiators to be dry.

[Ed Sirett]

You need to FIND the pump.

[Tony]

OK... I'll dedicate this weekend to the search..

Can you help me to narrow down the search.. The boiler is floor standing on the ground floor in the kitchen. The hot water cylinder is directly above on the first floor..

Is it likely that the pump will be VERY close to the boiler , is there any hints that may help me track it down without ripping up the entire kitchen floor, If when I find it I shall probably want to resite it to a more convienint location, can this be next to the hot water cylinder upstairs or does it have to be really close to the boiler.

Sorry to be a pain but I'm a little wet behind the ears on this one..

.. Tony

[The Natural Philosopher]

All the installations i have seen have the pump very close to the boiler, or sometimes the HW tank...

[Set Square]

So your boiler heats both the CH and the HW. How many water pipes are connected to the boiler? If there are only two, the chances are that both CH and HW circuits are pumped. In this case, the feed pipe will split at some point into the two circuits. The pump will be between the boiler and the point where it splits. So you need to work out where the pipes go. Mine splits in the airing cupboard - and that's where my pump is - but yours may be different. I've got solid floors downstairs - so my CH is distributed between the floors, and pipes drop down to each radiator.

But it sounds as if you have a suspended wooden floor downstairs, so your heating circuit probably splits into up and down - with the downstairs bit going under the floorboards. Again, the pump would have to be *before* the split - so under the floor is a possibility. Can you locate the pipes which take the CH upstairs? Can you locate the pipes which go the hot cylinder? They probably all converge somewhere near the pump.

If your boiler has 4 water pipes, it would suggest that the HW circuit works by gravity (convection) flow rather than being pumped. In that case, forget the HW pipes, and just concentrate on the CH pipes when looking for the pump.

Does your system have any motorised valves? If so, how many, what type (2-port or 3-port) and where are they? The possibility occurs to me that you may have separate upstairs and downstairs heating zones - and that the zone valve for upstairs isn't opening. When you turned off all the downstairs rads and just turned one or two on upstairs, did the boiler fire up?

You said earlier that the header tank is full. Are you absolutely sure that you're looking at the right tank? Assuming you've got a vented system, there will be *two* tanks in the attic - a big (~40 gallon) cold water header tank for the HW system and a small (~5 gallon) fill & expansion tank for the primary circuit. It's the *small* one you need to check - to make sure that its ballvalve is not stuck shut, and that there's a few inches of water in the bottom.

[Ed Sirett]

Identify every pipe in the house especially the heating ones and trace their routes. Making educated guess where you can't see. Istrongly suspect you have gravity HW and pumped CH. The pump must be on one of the pipes fairly near the boiler before it splits into various part of the house.

Ditto with any flexes or cables attached to boilers, thermostats or time switches.

Identify any 'boxwork' that might at first look 'structural' but is actually hiding the pump.

Trace the route of every pipe that leaves the boiler.

HTH

[Tony]

Found it, it was infront and to the rhs of the boiler in the kitchen under the floor boards.. I found it by spotting the electrical cable when I lifted the board near the boiler..

I've changed it to a Grundfos 15/50 it was a SMC Commodore 130. I'm about to balance the rads this afternoon .

All the LSV are leaky so I've got to sort that out first, it was suggested that I use sissel string and boss under the gland nut, I'll give it a go ... I'll replace the valves for new ones another day.

When I've got all this sorted , I'm going to work out the piping arrangement and jot it down on paper, see if there is any way to improve the design ( only if it involves minor adjustments )

Cheers..

.. Tony

[Tony]

Well as I've previously stated the new pump is in situ and set to max speed, the problem of the upstairs rads is still there.. All rads are open to supply now and I've found that they are all only warm to the touch, one is totally cold, (it has been bled and both valves are fully open, and it as previously been warm )..

The boiler is set to max - 80C so the manual says, but when I measure the pipes at one of the furthest rads, I find 57C inflow 37 outflow..the rest are not so hot..

Is the Grundfos 50/15 the right pump for the job, do I need a pump with a ' faster ' delivery?

.. Boy I'll be glad when warmer weather comes and I can turn off the CH

.. Tony