My house has three bathrooms and in only one of them, the hot water flow is extremely low at the bathtub. The flow at the sink in the same bathroom is fine. The faucet is a DELTA Monitor, no other markings I can find, one piece unit. I have tried adjusting the flow control and even removed it, but there was no change in the flow. The cold water comes out OK. Several months ago I had a plumber come out and $275 later he had replaced the cartridge and the flow had improved. Since then, the flow has again reduced to a trickle and I would like to avoid another $275+ plumbing bill just to have this happen again. Any suggestions?

FOLLOW UP question: How do remove the Delta Monitor cartridge so I can check it?

Follow up: While waiting for replies, I surfed some other sites including the Delta site and found my faucet. I took it apart and turned on the water. The cold side came out in a torrent while the hot side came out like a slow moving creek. I tapped the pipes hoping to dislodge any debris, but nothing came out. Now what?

Shut off water to tub,remove the handle, the trim plate, the trim sleve and the Bonnet nut P/N RP22734, now you be able to remove the cartrdge P/N 19804, when the cartridge is removed turn on the water for a few second to flush all the debris from the faucet out, assemble the faucet and you will be Ok see the image below, good luck.

John

I've flushed and flushed and made a mess, but the hot water side still trickles. Now what?

If you have flushed with cartridge removed and the hot water is coming out good, and trickles with the cartridge installed this indicates that the cartridge needs to be replaced, did you know that all delta faucets' has life time warranty, call their help line at 800-345-3358 and they will send you the cartridge for free, thank.

John

I've flushed with the cartridge out but the water still comes slowly with the cartridge removed. The cold water comes out and hits the back of the tub. The hot water barely makes it pass the spigot. I tried snaking a wire into the pipe but can't get anything both flexible and strudy enough to make the turn.

Sounds like you have a hot water supply pipe problem. Look for any vavles located before fuacet on the hot water side. Trace line all the way back to main hot water supply line. What type of pipe do you have. Is it my chance galvanized. Please let me know.

As far as I can tell, there is not a valve between the tub and hot water heater. Unfortunately, the only way to trace the pipe will be to tear into the wall and see where it goes from there (hopefully not into/below the concrete slab). The pipes are copper about 1" in diameter. There is an elbow that connects the supply line to the mixer assembly. I tried tapping in it to loosen any debris but don't want to tap too hard as to not loosen the solder. Not sure what else I can do.

How long ago the cartridge was replaced, if not too long call the same plumber he may come and fix it for you, Thanks.

John

If you have low pressure on hot side with cartridge out, your next step will most likely be to unhook hot supply from fuacet(yes I know this doesn't sound good, but has to be done). See if you have good pressure at this pipe(directly before it connects to vavle). Is yes, then clean or replace vavle(at this point it may be best to replace.) If you have low pressure at supply pipe, you have a problem further upstream. Can you tell whether you have sweat connections or threaded connections to vavle. May be that original installer used galv nipple, and it has plugged.

Im surprised that replacing cartridge fixed problem for a short while, but you say you have low pressure with the cartridge out. Let us know what you find, take care,

Lee